Z-moves need to be banned, one goes into a fight expecting an actual fight but then your tanky pokemon gets almost one shot by a first turn z move and its not FIGHT anymore, its like they introduced a stronger, 100% accuracy, no recharge needed, nor type immune (depending on the z move) hyper beam and giga impact, in a 1v1, a z move is as similar to making the "fight" one or two turns long depending whether you can actually survive it the first turn, it is absolutely broken and should not be allowed in a 1v1, even if you have SpD, Def or HP EVs it will most certainly lower your health to more than half or close to half at absolute best, specially mons like Hoopa Unbound and Naganadel doing a first turn Z move to OHKO even with type resitance when one just want to have an actual fight with actual moves and strategy. Offensive Z moves (or even non offensive z moves as well if you'll use that as your only defense idc ban those too) should be banned since its absolutely ruining the whole point of a 1v1 fight, which is using one pokemon to have a fight with another pokemon and with Z moves the "fight" part of the equation is removed altogether.
The issue I have with this argument is that you claim that Z moves get rid of all of the strategy in 1v1. Since 1v1 is so drastically different to almost every other ladder strategies are different from the other ladders. In standard ladders like OU a lot of the strategy is centered around switching, switching in your heavy hitter to offensively pressure your opponent, switching in the right check to the opponents mon to take advantage of it, switching in your hazard setter to make your opponents switches harder etc. A lot of strategy is very long term, trying to pick off or weaken the mon you need out of the way so your sweeper can sweep, trying to preserve the mon you need to stop the opponents sweeper from destroying you late game, trying to cripple your opponents problem mons with status to lessen their effectiveness. When you're team building your mons need to be able to take advantage of each other's strengths and support the whole team in a very general way. You're running stall? You need a status sponge like Gliscor or a heal bell user like Chansey. Running offense? You need a wall breaker to kill walls that stop your other mons. Try Mega Mawile.
Strategy in 1v1 is very different. Strategy is more focused on covering as many Pokemon as you can in three mons, in particular building to beat the most common threats on the ladder. You're movesets have to be specifically chosen, your Evs specifically tailored to beat what you need. X needs to bulk move Y from pokemon Z so that X can boost it's attack and kill Z next turn. Obviously there's an element of this in standard ladders but you typically have multiple ways to deal with any particular threat. In this meta you can often only afford one mon that deals with that Zard X, that Psych Z Hoopa U because your other mons have to beat other things. You complain about having to put a lot of Evs into a mon to live a specific hit or beat one thing but if you build it right than it should beat other things too. If can't beat anything else or no mon on your team can spare the Evs than either pick a new counter/check, build a new team or accept that you're gonna get 3-0d now and then. If you're getting 3-0d by something super common like Mega Gyara than you need to rebuild but if it's something obscure and unusual like Z Bounce Gyara than either accept the 3-0 or work out a way to kill that specific threat. There's so many things to cover that you're never gonna get it right first time but that's where you switch it up or rebuild, not give up and blame Z moves for everything.
And this is where the most important difference comes in. Predictions. So much strategy happens in team preview. One of you're mons beats two out of three of the opponents team but loses to the last mon. My opponent knows this so they'll pick that mon so I should pick this mon even though it only beats that one mon. Or maybe they'll see that coming so I shouldn't pick that mon. And so on and so forth. In standard ladders a bad pick at team preview will typically put you at a small disadvantage, maybe a big one if you fuck up massively. But you can play around it. It might go badly but you don't lose the game outright. In 1v1 your predictions have to be good or you might outright lose. So a lot of strategy is based around manipulating your opponent to pick what you want. Lures are incredibly effective in 1v1. That Zard Y might seem like it has a great matchup against your opponent and their Durant but if that's a Jolly Z Stone Edge Durant than that's a hard loss bucko. Your Donphan is going to head smash that Zard X to death and then it's 252 Hp/ 252 Def with Will O Wisp and roost and your Donphan isn't even getting a 2HKO. Using lures (good lures now, not shuca berry Klingklang specifically Ev'd to beat Stunfisk or something like that) can really ease your prediction game.
or just use Shedinja to force your opponent to pick something with the coverage to beat it like some kind of animal
Now on to your complaints about Z moves themselves which have been covered already but still. There are typically two types of offensive Z move users. The first wants to outspeed and kill you before you can attack such as Zeraora and the second wants to live a hit through bulk or sturdy and either kill you or lower your speed with bulldoze, rock tomb etc. such as Donphan. Both have issues. Fast Z move users need to be fast obviously and that means they need to invest Evs into speed which means they have less Evs to put in attack or bulk. So many Pokemon simply can't function like this because they need both an attack boosting nature
and a speed boosting nature. Either they can't outspeed or they can't KO you. And if they can have both the speed and offensive potential they can't have the bulk to live hits if they are outsped by say a choice scarf user or if they can't kill and have to take a hit themselves. The other bulky archetype typically requires minimal speed so they can focus on attack investment and however much bulk they need. But since they're slower they're more vulnerable to being statussed or having their stats lowered by Charm or Eerie impulse or the like (which are good in this meta cos you can't just switch). They also give you time to boost your defenses and live their hits easier. The point is that both have issues and can be played around.
And this is where we reach the crux of the issue. There is no one counter to every Z move user because there is no one Z move user that beats everything. Banning Z moves because they boost the offensive potential of many Pokemon is like banning choice scarf because it let's many Pokemon outspeed things they couldn't otherwise. It's not like Z moves have no drawbacks either. If you do sponge the hit and heal up than the opponent has a useless item that doesn't help at all anymore. A Z crystal typically only boosts one of your moves meaning your coverage takes a hit whereas if you had a specs or band that wouldn't be an issue. If you effectively resist or are immune to the opponents z move than they can end up pretty ineffective. They also can't use a scarf and thus might not be able to hit important speed benchmarks. Your Z fly Salamence might be able to kill that Pheromosa four times over in one hit but if it's outsped and hit with an ice beam then it doesn't really matter. Scarf outrage would just do that job better (though you're better off using Dragonite). Z crystals are really good items but just like every other item they have pros and cons and have enough opportunity cost that they aren't always worth it.
If you
really, REALLY hate being killed by a z move first turn than use a prankster mon with substitute but there are probably better options available.
Hey I'm finally contributing to a thread that I've been lurking for over a year yay