You write with a lot of contempt. Some of this was indirectly targeting me as the guy who told you to get better at positioning. This contempt is not helpful. Similarly, the post has a number of allusions to sets and items which are largely unpopular/aren't seen at moderately high levels of play. Adding these extra points is additionally unhelpful. I will refrain from harping on these and will leave the tone and questionable choices within this post alone for the rest of my own post.
Correct me if I am wrong, but air balloon diglett is certainly seen in high ladder matches and tournaments, and there is direct discussion about it on the fourms and in the viability rankings. Memento Sunny Day diglett was one of the best sun setters in the tier as far as I know, so saying memento diglett is unpopular or absent at high levels of play is strange. Sure, Sludge Bomb diglett may not be the most common thing in the world right now, but if your team has a cottonee problem (particularly worthwhile because it would otherwise counter diglett quite well) it certainly can be worth it. Earth power diglett and giga drain trap and pretty standard as far as I know because they can take out onix more reliably, a huge target of trapping. endure berry juice trap I have also seen on mid ladder as it allows it to potentially trap multiple targets and aids in its overall reliability. Again, what I am saying is that diglett can be easily customize to beat a threat your team is weak to
and it is extremely difficult to scout this safely.
You start by saying trappers are able to be used on basically all archetypes of teams; this is fine. You continue to say that they enable Pokemon to sweep. I would argue that this is fine as well. It is worth comparing what you have said above to a pretty solid rhetorical counterpoint in Mienfoo. Mienfoo can be added to almost literally any team and improve it. Mienfoo can be used on all archetypes and is pretty likely to be overlooked, due to its omnipresence, as an important part of enabling type spam strategies. This is to say, that your introductory points do not touch on points that speak to trappers being demonstrably problematic unless Mienfoo is as well. Granted, there are shortcomings of this rhetorical device, but that is why it is only being applied to this pair of points rather than the rest of what you have to say.
Mienfoo does not guarantee a kill every single game, mienfoo does not have a arena trap ability. Yes, clearly mienfoo is a good pokemon that can be put on a variety of different teams. The problem is that a trapper, who gives you a very powerful tool as your disposal (not just in battle but in teambuilding) is nearly as versatile and splashable as one of the best pokemon in the tier. Should there not be a trade off for this? I have not really brought up wynaut in my post, but wynaut is a trapping pokemon with little merit outside of that, which is an opportunity cost. Trap and Dig have no where near the amount of trade off here and have similar utility and support capabilities to our best pokemon in the tier.
You are carrying forward assumptions that something is already broken and merely listing every set it has ever used. This is not an argument unless you could expand on why these are issues; don't make us need to assume what the offense is here. Air Balloon has more upsides that simply beating other trappers; granted that is the major point about it, it also avoids being countertrapped, matchups up well against Sticky Web teams, and also still has use against Onix. This aside, there is nothing wrong with Pokemon running different items. There is also nothing wrong with Pokemon having a lot of good moves to pick from. I would continue to say that even if there was, you haven't presented a variety of inherently overwhelming options. Diglett only has 4 slots like any other Pokemon and the options it can pick aren't particularly impressive when taken on balance. The most extraordinary thing about Diglett's variety is its item selection; in truth the moves it selects largely secondary for considering how you can combat Diglett in a match. The direct consequence of this is dealing with Diglett often ends up being fairly straightforward, especially when you are aware of the item.
The problem here is that trapper move and item choices allow a degree of versatility that is difficult to scout and provides it with immense support capabilites tailored to a team. I have already mentioned some of the move choices above, and I think you are downplaying the importance of this. Anyone who has seen my posts before in past gens know I love creative sets and cool item / move choices and are innovative. As you have said, there isn't necessarily anything wrong with that. The problem in this case however is that it is very difficult to scout diglett sets because they can be very team dependent with little to no functionality costs. For example, life orb diglett cannot easily take out Ponyta-G if your team has trouble against it, but you don't have to worry about that because eviolite allows diglett to trap and kill it with little issue. Another example is that your standard eviolite trapinch cannot switch in and trap scarf vulpix under usual circumstances. However, if you take those def EVs and put them over into special defense and use berry juice, trapinch can now switch into a Weatherball or Fire Blast in the sun and take it out the next turn. In terms of moves, final gambit is pretty significant: staryu, who is generally fairly safe against diglett between rapid spin, recover, and water STAB. can fall to final gambit diglett. It also opens up Ferroseed to be trapped and killed as 84HP Ferroseed only has 22 HP total, so diglett either leaves it with 2HP or just needs minimal chip from a u-turn, knock, entry hazards, etc. Keep in mind this still retains trapping coverage on onix, whose weak armour or head smash sets tend to have 21 HP at most and life orb abra sets.
These are pokemon that you typically assume would be safe from trapping (esp. staryu) succumb to it. This complicates your defense of trying to avoid being put in the position of being trapped because in order to do this you must be aware what on your team is able to be trapped and when. For example, I would think most players play their staryu without as much caution if diglett is on the other team because they know it can usually beat it 1v1 if it is healthy. But Final Gambit turns that on its head and it can be very costly if that opposing team happens to be hazard stack. And again, it is extremely difficult to scout these sets because you cannot see how much HP diglett has, cannot gauge eviolite or berry juice trap until it switches in or takes an attack, cannot tell life orb diglett until it attacks, etc.
I suppose I did not elaborate too much on why air balloon is a problem. As you have said, Diglett carrying air balloon is a direct result of people employing trapinch to get rid of diglett. This naturally causes some games to be trapper vs. trapper and the player whose trapper comes out on top is at a heavy advantage. Sure, air balloon makes switching into onix easier, but its not like diglett has any difficulty in trapping onix to begin with, as eviolite or sash earth power sets can deal with onix fairly well in addition to the final gambit set. Again, I can see avoiding Sticky Web being a benefit, but you can also see it as diglett avoiding potential counterplay to its trapping.
If you fail to see how the defensive qualities of a Pokemon which needs to come in to pick up its KO are relevant to examining its potency and level of viability in the metagame than this conversation is a nonstarter. You have already come to your conclusion at this point, and a reader has not been provided arguments enough to join you here. You have also inverted the premise of your argument to say those Pokemon support trappers and give them too many opportunities when you opened your post with the statement that trappers are broken because they can support type spam very well. While these premises are not mutually exclusive, how you substantiate these points creates a logical framework where trappers/Diglett: a) do not need to switch into anything, b) can be pivoted in on anything they'd like to trap with ease, c) can switch into some of what they would like to trap, d) trap pokemon such that what has pivoted Diglett in now wins the game for the other player.
By no means do trappers absolutely
need to have pokemon with pivot moves to be successful. I was pointing out (which you did not seem to address in your post) is that they can overcome these weaknesses very easily and it is not as easy to exploit these weaknesses when are patched up. They do this through their item choice (eviolite, berry juice, sash, air balloon all in some way ease the ability to switch in to trap to some degree). U-turn and the newly reworked teleport also help immensely in the ability of trappers to do their job. I could maybe buy your argument if teleport or u-turn or flip turn were uncommonly used niche moves in the tier, but we both know that is simply not true; they are all over the place in LC and will always be used regardless of trappers being in the tier or not.
On its face, you're also ignoring the qualities of Pokemon with these pivot moves have in generally negating their counters as a quality of pivot moves. Further, there is a consideration of if this is outplaying your opponent, and with the usage of Teleport I would gladly argue that it may be.
Like I said, I have been around these forums for a while. If you're trying to convince me that pivoting moves can be considered "outplaying" the opponent and thus should not heavily influence a suspect or ban, I can easily point to gilgar being banned in gen 5 (mostly for acrobatics, but it was also the best support pokemon in the tier with sr and uturn) , TangMa teams in gen 6 (or really just yanma in general that meta was dumb lol) followed by misdreavus and flecthling cores (aided by uturn) which ultimately lead to missy being banned, and most recent our rufflet ban, which its access to u-turn certainly influenced its voters to ban it.
The above framing of trappers in the metagame is a very static understanding of playing the game. I do not mean to demean you, but when you also opt to simplify my advice down to "don't get trapped with your pokemon!" you have a key misunderstanding of this tier and the dynamics that very good teams often engage with. Why is the idea that your (insert trappable Pokemon here) cannot revenge kill something freely fundamentally flawed? In what way does this fail to align with the nature of planning ahead in singles? You have created an unhelpful heuristic about how to win in Pokemon (e.g. kill their 6 before they kill your 6) which ignores the many skill gaps that LC has. You are making your decisions with a flawed perspective if to you "the literal objective of winning the match" is to simply have concluded the match. You have framed the game around what you cannot do. In every strategy game that exists, the player ought to be chiefly concerned with what you can do. Winning in Pokemon is trying to optimize your choices; the choices which you cannot make are part of the game as much as the choice you can make.
Switching is what makes pokemon competitive. Removing the option to switch is removing what makes pokemon, well, pokemon. We don't play a game where our line up is set in stone and a series of 1 on 1 happen. Switching is a part of the game we play and part of the agency that we as players have to minimize the negative consequences of mistakes. Your argument here suggests that one of the ways to handle trapping is looking at a player's team, determine what on your team can be trapped and what is relatively safer, and plan accordingly. A have pointed out a problem with this in that you do not know what that trapping set is, and it can be very difficult to tell what is through preview alone. You may assume that your healthy staryu can be free from being trapped, but final gambit ensures that it is not.
Players should always be allowed to make the optimal play at any given time to advance the game, but trapping forces players to make sub-optimal plays that are sometimes not able to come back from. Or, in some cases, these goals are impossible or difficult to achieve, such as getting rid of the trapper first. Right from team preview, trappers put an absurd pressure on you to not misplay. I would argue that this pressure is mostly unnecessary, especially when such pressure does not come with a significant opportunity cost. On the other hand, the player employing the trapper has all the power, because they are allowed to minimize their mistake if they happen to come in on the wrong threat. Now, you can argue that the player is still in a disadvantageous state, but being trapped means the opponent's move is all the more telegraphed because you know they need to attack. In fact, having a trapper on a team gives a player too much leverage against the other for relatively little effort and cost. Do you want to live in a world of pokemon where you can say you lost a battle because "I misclicked my onix and lost it to a diglett or a trapinch and then rufflet ran through my team?" I don't.
Sometimes, you cannot avoid getting trapped. That sucks. It feels bad. But you can do a variety of things to make the best of it and win the game despite losing your Abra/Ponyta/Mareanie/etc to a Diglett. You can make choices with the known variables of the trappers on the other team and your best outs to win. You can position yourself to make progress when the trapper picks up a KO; you can set up on the trapper with a limited number of sweepers; you can revenge kill them; you can take the turn to send in something like Scarf Mienfoo to pick a KO with High Jump Kick. This is the basics of what I was telling you of. The objective of winning the match is often managing the shifting variables of limiting your opponent's progress while advancing your causes. The effect on the player does not need to be passive; otherwise, it genuinely would be incredibly hard to overcome Diglett teams after they secure a KO.
You can apply this logic to nearly everything that we have banned in the past. Sure, rufflet is broken and gets a kill everytime it comes in against my team. What can I do to capitalize on this? Well my scarf mienfoo can outspeed and pressure the team so I'll go with that. Life Orb Gastly 2HKOs basically everything in the tier, so I better not let it in for free on anything, so better be careful of my oddish, etc. In some cases, there might not be a feasible way to make progress or advance the game, or that way might involve your opponent's own misplay. You also gloss over just how many 50/50s trapping can force in those scenarios, most of the time the player with the trapper getting more reward out of that 50/50.
One last note on this is that you have a comment on team structure; that is another point which I think is weak. If you are finding that most of your Pokemon are getting isolated and trapped, the problem is not necessarily the trapper but rather the choices you have made with your team. Yes, teams can and often do run trappable Pokemon together, but they should not do this without a way to punish being trapped. Not all team combinations have the right to be viable either, and as a player which is concerned about the state of the metagame you have the obligation to be building teams to address the meta trends and the tried-and-true strategies.
Any potential reward you get from "punishing" trapping is overall not going to be as beneficial to you as the other player trapping your target because you cannot choose the other player's response, while the opponent with the trapper got to decide what Pokemon you were losing and when. Oh, and they are probably will do this with switching, which lets them minimize the risk or potential downside to trapping, which you were not allowed to do.
This section largely is against Smogon tiering policy. I will engage with it to the extent that I feel is relevant for highlighting how Diglett is not to blame for much of this. Most of the electric types in the tier would be bad anyway; Chinchou has been the best it has been in years only two months ago and it negates these electric types. Similarly, Magnemite has continued to be fairly good throughout the years despite trappers. Your wistful speculation about what could be does not belong in a conversation about suspect tests. I can again refer to the colored history of Magnemite (sans useful teleport) and Chinchou throughout ORAS and even SM LC to underline why your concern for the viability of these trapping weak Pokemon is not a valid concern for tiering. Cufant, Croagunk, and the like may have "obvious niches" but that is not a concern for anyone engaging with tiering policy. We should reflect that this particular line of thought is entirely speculative, is flawed, and can only be done by flawed humans. This is why questions about how Pokemon which are dominated by other Pokemon are disregarded at the policy level.
Your argument is fair to a certain degree, that we shouldn't necessarily care about all electric types, but I think to say Chinchou and magnemite are fine in viability is a bit of a stretch. You could use Mag to combat the special attackers in the tier, but that substitution isn't really viable because ferroseed is not as easily trapped as magnetite is. Chinchou cannot even use electric moves while a trapper is in the back, while even magnemite can use sturdy + teleport to get out of trapping in a dire pinch. [/QUOTE]
In this last section, I'm not sure what you are hoping to communicate with us. With regards to Air Balloon Diglett, this is an arbitrary line in the sand. With regards to trappers removing checks and trying to point to Pokemon which are currently banned for having too few checks or winning too easily, Diglett is certainly part of the consideration with these suspects. The nature of statements that Diglett makes these Pokemon broken, has pushed several Pokemon over the edge, or something of this fashion, are hard to substantiate and are part of a much broader and deeper conversation. I will refrain from itemizing the LC ban list and engaging with this point any further as my above words should round out a better framework for why Diglett is not broken or worthy of a suspect.
I really do not think that air balloon diglett is arbitrary line. It is indicative of a metagame where trapping is important to the degree that users feel it is necessary to combat other trappers and assume their use, implying trapping's prevalence and overall impact on battles. I certainly think that this is one reason why it should be looked at.
