(Offensive teams) can only "prevent Mence from setting up" if every single one of your Pokemon is a Mence check. And I'm sorry, but you can't make an offensive team (or any team in general) with 6 Pokemon that beat MMence 1v1, or you will literally just lose to the rest of the metagame.
That's not quite right, instead if means that you need to be careful about the timing and placing the checks in/out of the field. (which is exactly what high level pokemon has always been) For example, if you currently have something out that is setup fodder for mence but kills whatever is in front of you, then you need to think twice before simply killing it. It'd probably be better to switch to something that can not only deal with what's on the field but can also threaten/prevent salamence. Voltturn would be the best move to have in this case. This is a very common situation for every sweeper in the game. It is easier for defensive teams to do because they usually have pokemon that wall/check/counter multiple things (whatever the opponent has on the field) and can also attack or cripple mence (depending on set)
If you need to run both Thundurus and Skarmory on the same team just to deal with one threat then something is very, very wrong. Running multiple checks to one Pokemon=making yourself much weaker to everything else.
But that's exactly what I'm trying to refute, because everything that works well against mence is also very useful against thinks like kyurem, latios, pinsir, garchomp, talonflame, landorus, basically anything that shares a common typing and plenty of other random things (i.e. skarm will beat scizors and excadrills too). Not only that, but having tools like prankster or just a flat wall on your team are useful in a large variety of situations as well. For example, having both thundurus and skarmory on your team isn't a bad place to start at all (even if mence was banned) and then just build around it. It seems to be a balanced approach. A more offensive team could use thundurus/greninja/weavile, which are all very good against the whole meta at large. Running mence checks doesnt make you weak against other stuff
-if the team is well built!-
You say that the only way for offense to beat MMence is by "guesswork" (which in itself is pretty distessing), but that's not even true in the first place. There is literally no skill or prediction or guesswork involved in using MMence, especially the Sub set : just Sub on defensive stuff that can't touch you, Roost on offensive threats that can't 2HKO you to stall them out, DD if doing so lets you win from there, spam Return otherwise. No skill at all.
Every pokemon running sub or boosting moves does the same thing -_- it's not skill-less to actually manufacture the situation in the first place where you actually freely get in on something and have a chance to set up. It is HARD to do. Between double switches, voltturn, priority, surprise/gimmick sets, what have you, getting setup doesn't just magically happen every single time.
Almost every single high level replay ever since 4th gen has always come down to complete guesses or predictions or luck at the end (should I attack them while they boost? or should i switch to a soft check while they attack me? should I attack while he tries to substitute? or should I status while he tries to roost?)
Every high level game right now, just as before, is going to come down to the same sorts of thing. Should I toxic it while it roosts? What if it subs? What if it isn't a bulky set at all and I can just 1hko it? This applies to every threatening sweeper out there. Almost every good game between offensive teams has always been decided in the final turns where someone guesses wrong (think prankster taunt twave thundurus vs the entire meta, a few months ago, where everything is speed ties and guessing their final move) More offensive teams have to get the guesses right more often whereas bulkier teams often an afford a few more mistakes.
okay here we go. Fairy/ice/rock/dragon attack users usually ... loses to ... needs be scarfed ... can't switch in... being "useful" isn't enough ... you can't even use the word "check" ... you literally just listed all the thing that don't straight up lose to it ...
Why did you phrase everything that way though? Pointing out the weakness that each check option has? It's just as valid to list it out like this:
sub/dd/roost/return loses to xxxxx, yyyyy, zzzzz, etc, etc
dd/refresh/roost/return loses to aaa, bbb, ccc, ddd, etc
dd/3attacks loses to 1, 2, 3, 4, etc etc
dd/facade/return/roost loses to q, r, s, t, u, etc etc
4attacks loses to w, x, y, z
And so on. Ofc you can break down each check and decide which mence set will beat it. And you can likewise beat each set. <_<
Look, there are 1000s of people all at the same skill level roughly at the top of the ladder or who could compete equally in a tournament. As soon as you click "Find Battle" you have a 50% chance to win or lose. And anything higher than 50% is actually magnificent considering you're fighting people exactly the same as you.
You can't cover every mence set and you can't cover every [[
any OU sweeper]] set either, with only checks. Many OUs don't have any true counters at all.
I literally have never seen a Porygon-2 in OU before ORAS besides a couple of Trick Room teams. Now it is everywhere. How is that not overcentralisation? Also, how is the fact that everything is running an Ice move not proof of overcentralisation too?
Porygon is being drawn up by multiple forces, not just salamence. It's good against greninja, slowbro, all kinds of things. It has been common on stall teams for months before. But stall wasn't popular due to heracross and gardeoivoir and other things like that.
All the HP Ice things are used by electric types and boltbeam has always been a thing, it's even more important now.
It is centralizing but debating whether it's normalcentralizing or actually overcentralizing just sounds exhausting.
It's not overcentralizing yes it is
It's not restricting teambuilding yes it is
It's not uncompetitive definitely uncompetetive
It's only banworthy if nothing will ever drop from ubers. If things slowly start to drop in for research and OU gets a massive power creep in general (regardless of its effects on stall) then things should just wait until then. In such a situation, you could have 2 random salamence checks (like greninja and rotom) on your team and they would also be useful and fare very well against the entire theoretical OU. And you'd win against some mence teams and lose against others.