Playing tiers where they are legal together? Natdex, while nowhere near a 1to1, is a glimpse of what it's like.
Wow. This is way too much to address. I'll start with this. Although I don't play a ton of Nat Dex, you have to keep in mind the options in Nat dex to deal with it are greater both in mons and movepool. I don't think it's close to the same. Like, they banned Ghold in Nat Dex but not OU. In OU, hazards are sticky and we keep banning mons because teams are being stretched thin in the builder, among other things.
Another thing you might notice with OU is a general lack of fast Electric types. It is mostly Bolt and the occasional Zapdos. Jolteon is too weak to be more than very niche and Regieleki is banned. If Regieleki was ever unbanned, that would be another issue to consider with Koko.
Koko's electric moves without a boosting item just don't hit that hard into defense, and offense has ways around it (Iron Crown literally stuffs it, and abuses its terrain to use against it). Also mixed/physical are not sets. Please don't.
And
with a boosting item? That's the problem. Or one of them. Set diversity being another.
And before you say mixed sets can't work again, I'm calling cap on that. I see no reason why you can't carry Wild Charge, Thunderbolt, or maybe even Electroball (more debatable) on some sort of mixed set that has mostly moves from the other spectrum. If they don't already exist, I'm pretty sure one could be made.
You often don't need quite the same raw power on mixed because a lot of walls stray towards one or the other. It's also possible to sacrifice a bit of speed if you are focused on just wallbreaking. There are also set up moves like Agility and Calm Mind to make up for it. E-seed + CM could probably run something like Acro/Thunderbolt/Tera Blast. In one turn, you would be +1 in 3 stats and nobody would see it coming. Honestly, I would go on further if that was relevant to the tier. But the insinuation that mixed sets cannot work seems close minded at best.
Zama legit can easily tech speed to outpace and beat Koko longterm. Boosted Body Press easily breaks it down (+2 BP 2HKOs offensive Koko).
Sure, but you resist BP and, if we are playing the counter set game, can run items like Choice Specs or Electric Seed. Zama isn't going to want to trade damage from Dazzling Gleam or maybe even Acrobatics without Tera Steel or something. And you certainly aren't going to want to do that before you are even set up. Zama can't come in on Koko and just set up very often.
This seems to assume Zama came in on something else
and set up prior over the course of an entire game. All this really says is Koko isn't the best RKer for Zama. Not that Zama is going to stop it from doing its thing that much.
Regarding the "opposing quark mons don't work as answers"... just not true at all. You're not gonna argue that koko standalone is a broken offensive threat with Tera (it's not even close), and as an enabler it's just good. You can't argue that it has too many sets, because the only "dangerous" sets would be specs.
I'll admit I glossed over this first part, but Koko is a pivot. Or at least tends to have pivoting moves. Teams with it are generally going to be very good at gaining momentum. These Quark Drive mons as counters to Tapu Koko would be anti-leading or attempting to RK most of the time. Almost none of them are going to want to risk coming in on an Electric move or U-turn into something that deals with them. I also feel like Koko could just straight up win the exchange against Valiant in a turn even if it was out sped, unless Valiant decided to Tera. Koko KOs and Valiant doesn't.
Thinking about the
actual OU tier, mons like Valiant and Moth are already top tier without the benefit of E-Terrain. And it has already pointed out how some others could be good in
OU.
As far as other sets, I don't know why you seem to think Specs is the only viable damage multiplier item to ever run on it. You could run Choice Band with U-turn, which goes off the same Attack stat as Gouging Fire by the way. You could run other damage multiplier items like Magnet, Expert Belt, and Life Orb. Something like Expert Belt with TB could be particularly devastating considering Ice is super effective to like every Electric resist. Even something gimmicky like Swagger/Mirror Herb is a potential option. Do Nat Dex players lack creativity or something these days? Not a snarky remark. I'm legitimately asking since I don't know.
Boots attackers aren't THAT strong, screens are just an alternative (not even the best) to screens Deo-S, and what are support sets gonna do? They're not breaking things either. Yes it's versatile but it's not breaking anything in that versatility at all or anywhere close to it.
This seems really silly.
Boots attackers aren't THAT strong? Then don't run boots. Run hazard control and an item for damage. Problem solved. Treads is even a Quark Drive mon and Koko can pop Air Balloon Ghold for it.
Screens are just an alternative to D-speed? You mean with Electric Terrain support? Isn't that entirely different? If you are talking about Koko as an enabler, isn't this something that should be considered? Screens + Electric Terrain on Koko is arguably bigger than Screens + Snow from A-tails is for Cetitan considering all the Quark Drive mons.
What is a support gonna do? I don't know, maybe run some moves like Taunt, Defog, T-wave, Toxic, and/or U-turn? I don't know if Koko would get Defog in S/V, but it has it in Nat Dex. And you keep trying to use Nat Dex as an example for OU.
The problem with versatility is that it can require different things. If you are worried about specs and get band, you might be losing a mon. If you are worried about offensive Koko and get screens, maybe it sets up 1 or 2 screen and U-turns into some Quark Drive mon your team can't deal with as well. And if you are worried about different coverages, expecting one set can get you blindsided by another.
Even if you think everything is good yet not too much, the emergence of even one set being so could make all that versatility far more problematic. But in Koko's case, that doesn't just go for it but any mon it potentially enables.