Why Gen 9 OU sucks and how it may be able to be fixed. (Reposted from Reddit)
This is probably my least favorite OU to play. Every game feels like an RNG coin toss and the metagame is incredibly stale. I'm confident I'm not the only one who feels this way about OU so here I'm listing my main gripes with the tier.
Ban. Ban. Ban.
Get Kingambit the fuck out of OU. Ban the incredibly uncompetitive mechanic "Terastalization". (And unban Pokemon like Regieleki/ Volcarona) If Dragapult becomes too much? Ban it. If Gholdengo hazard stack chokes the meta too much? BAN IT. The stigma around banning Pokemon has been around since the inception of competitive. Generation 5 is where we see it at its previous worse and wow, the tier is shitty and dead. Freedom Cup unbanned a lot of mons that casual players wanted in OU aaannnddd: The tier was completely awful and died after two weeks. We already know what happens when we don't put our foot down and deal with something problematic. This tier can still be saved, but only if people are willing to recognize that what's "cool" isn't what is best for the tier.
TLDR: Play Advance OU because nothing will change and the tier will go down its unfortunate trajectory and ADV is Goated.

This is probably my least favorite OU to play. Every game feels like an RNG coin toss and the metagame is incredibly stale. I'm confident I'm not the only one who feels this way about OU so here I'm listing my main gripes with the tier.
- Terastalization - This mechanic is bad enough on its own, but when combined with all the other broken factors, not only does it encourage coinflips (Which I absolutely hate), but also kills any semblance of reliable defensive checks in the tier. Example: Kingambit abuses Tera Fairy/ Tera Flying to destroy the Great Tusk matchup. This is absolutely an uncompetitive mechanic that does a lot of harm to the tier, as well as pushing Pokemon like Volcarona (Which could help check Iron Valiant) over the edge. Even if not that many Pokemon would be unbanned if Tera was banned, that doesn't change the fact that Tera still makes what should be good matchups and completely flips them, destroying any semblance of defensive reliability.
- Kingambit - It is insane to me how a Pokemon as blatantly broken as Kingambit is allowed in the tier, I just could not fathom how some people are only NOW realizing this thing is stupid after it overtook Great Tusk as the #1 most used Pokemon. Great Tusk is a fake check that can't do anything if KIngambit becomes a fairy and clicks Tera Blast, and if Great Tusk can't handle it, how is it not broken? The only reason Kingambit is somewhat reasonable right now is that Willo-Wisp is very Common and Iron Valiant can eat a Sucker Punch, not to mention the numerous defensive Teras such as Fairy that has been popular for a while, stuffing sucker punch being a valuable benefit. Dondozo has also risen in Popularity which is the best counter-pick to Gambit, sporting massive defense and unaware. Yet, Gambit still sweeps teams very often and is still a menace. Tera Fire/ Lum Berry can punish Willo-Wisp spam. Tera Dark Black Glasses Kowtow Cleave with Supreme Overlord boosts heavily pressure Dondozo. Defensive Teras allow Kingambit to alleviate the reliance on Sucker Punch and take out sets that were supposed to beat it. This mon is quite nice defensively I'll admit, but there is no way to justify this menace warping the entire meta around it because it checks other mildly broken Pokemon like Dragapult.
- Not as stupid but still pretty stupid game-ending threats - Baxcalibur completely sweeps many teams with just two Dragon Dances. It is absurdly powerful and giving it any room to set up (which it can force with Tera anyway) can be a death sentence for any team not packing Dondozo. Or how about the terrifying Booster Valiant, with seemingly endless amounts of variation and the ability to completely wipe teams in the end game lacking proper counterplay? (You thought Slowking G could beat it? Watch it use +2 Tera Dark Knock-Off and delete your chance of winning the game) And then there is Sneasler, with terrifying offensive potential and access to Unburden. There are many, many ways to activate it. (The newest one is using Fling with a Big Nugget and destroying Pokemon like Slowking Galar and Gholdengo). The amount of threats you have to account for to make a half-decent balance core is stupid and makes teambuilding balance painful at times.
- Limited Hazard Control - In a meta where every ground type learns Spikes and there's a Pokemon throwing around STAB 97.5 BP hazards, The lack of good hazard control is absolutely egregious. The removal of defog from everything, save for a few Pokemon like Corviknight, already makes Hazards a problem, even with the presence of Heavy-Duty Boots. What really makes hazards feel absolutely insufferable is Gholdengo. It spin blocker that also blocks Defog, thanks to Good as Gold, and with Defog distribution getting nerfed, the only OU-caliber Pokemon with access to Defog is Corviknight, a Pokemon that is absolutely tooled by Gholdengo. Great Tusk is supposed to "shut down" these team styles, but in reality, it's been unreliable for a while. Gholdengo slams it for massive damage with Make It Rain, so Great Tusk usually isn't excited about having to deal with Gholdengo in a 1v1, especially if it's holding an Air Balloon. While Great Tusk can knock off the switch, a Pokemon like Iron Valiant can very easily be brought in and punish Tusk for not rapid spinning, meaning Tusk is susceptible to failing at keeping hazards off the field. Not to mention doubling up on Ghost-types such as Dragapult makes Tusk's life even harder. The only other counterplay is a Court Change Cinderace, which is flawed. 1: Cinderace is naturally frail and has a tough matchup against Hazard setters, 2: You don't really want to set up your own Hazards, and 3: They would set hazards up again and Court Change is useless. The hazard meta is an ass.
- Overcentralization - Every team is Tusk; Gambit; Bax; Valiant; Hamurott; Glowking; Dragapult; Gholdengo; and a less viable but usually OU pick. Teams are incredibly stale and the meta forces it to. Why not run Gholdengo when there are so many dangerous threats like Iron Valiant and Sneasler running around? Why NOT run Tusk when it's still one of the better Gambit answers and a rare source of relief from Hazards? WHY use a shit-mon from a lower tier when all the top tiers are so much better? This meta is a fucking disaster.
Ban. Ban. Ban.
Get Kingambit the fuck out of OU. Ban the incredibly uncompetitive mechanic "Terastalization". (And unban Pokemon like Regieleki/ Volcarona) If Dragapult becomes too much? Ban it. If Gholdengo hazard stack chokes the meta too much? BAN IT. The stigma around banning Pokemon has been around since the inception of competitive. Generation 5 is where we see it at its previous worse and wow, the tier is shitty and dead. Freedom Cup unbanned a lot of mons that casual players wanted in OU aaannnddd: The tier was completely awful and died after two weeks. We already know what happens when we don't put our foot down and deal with something problematic. This tier can still be saved, but only if people are willing to recognize that what's "cool" isn't what is best for the tier.
TLDR: Play Advance OU because nothing will change and the tier will go down its unfortunate trajectory and ADV is Goated.