As much as I hate Tera, imo if anything can kill the tier it would not be tera, but rather pple being doomers and ranting over how they think the tier is absolutely unfixable and nothing should be done anymore.
Bans have an impact on the tier: yes, the tier is in an unbalanced state right now, but saying that no progress has been done since we had absolutely insane shit like Regieleki, Chi-Yu, Deoxys-Speed, Regieleki, or even the fucking abomination that was Shedinja is just a blatant exaggeration. Even more recent bans, such as Annihilape or Espathra, pushed the tier in the right direction.
I believe it is time to stop crying about it, move on, and do what we can do to save the tier - and we will save the tier.
Stored power needs to go. Its abusers are fine without tera but since a tera ban is out of the question we have to look at the other common link. Tera poison stored power cresselia and mew are certainly not healthy parts of the metagame at all, while tera fighting polteageist beats all the previous counterplay it had back in gen 8. Either you ban these mons or you ban stored power. And there's no way you ban cresselia and mew and teapot lmao. 
Kingambit holds the tier together by trapping the ghosts, being extremely easy to slap on literally any team, and crushing a lot of the stupid cheese running around. Unfortuntely, teraing into a different typing lets it beat its already limited pool of checks in Tusk and Zamazenta while tera dark boosts its power to absurd levels. This mon is immensely important to metagame health but is itself stupid with tera, so it should be suspected moving forward. However, I'm not sure how inclined the council is to suspect things anymore due to the nd playerbase having clearly demonstrated its incompetence. 
This mon is invaluable speed control for the tier but unfortunately becomes broken if kingambit goes. Should probably be suspected anyway since tera dragon draco lacks reliable counterplay and QBed if kingambit goes. 
This mon is also extremely important for the tier as it is the linchpin of hazard stack teams and provides a unique defensive profile that allows it to act as one of the few checks to scary mons such as Sneasler and Tapu Lele. Without tera, it has plenty of counterplay, most notably in Kingambit but also Gliscor, Clodsire, Ting-Lu, Volcarona, and Heatran. Unfortunately, tera for some reason is staying in this tier so if it teras into say a water type for example, it is actually able to use a lot of these would be checks as set up fodder (or turn revenge killing attempts into another lost mon). Not to mention if Kingambit leaves, then Gholdengo becomes much more difficult to deal with. Should also be suspected. 
Unburden is broken with tera. Dire claw isn't even the issue imo, it's that its tera flying unburden set is basically mega hawlucha and runs through teams without gholdengo. You can also see different teras such as ground, dark, ghost, electric, ice, whatever. It doesn't matter if they are suboptimal- they exist and u will or have run into one of them and lost your check and as a result the game. Needs to be suspected.
This mon is dishonest. Volcarona has always been the matchup moth, but now you also have to play around its several different viable tera types such as grass, water, ground. It's less dominant than in svou and fine for now but people should absolutely keep an eye on it. 
This mon is very dishonest in a different way. Tera lets it escape its poor defensive typing and turns it into a nearly unkillable chip damage machine. It is extremely annoying to maneuver around and has by itself made covert cloak a real option on pokemon. So many teams just fold to this mon so hard and in extreme cases get 1v6ed. Worth watching for now. 
I honestly think this mon is probably fine even with tera but people should keep an eye on it as if both ghosts go, there isn't really a splashable cc or body press immunity anymore. 
