While I'm not entirely sure which way I'd vote on a Goth suspect, I'd like to give some pushback on the idea that it's an uncompetitive mon. Most arguments around Goth being broken bring up its matchup reliance and its ease of use, and both of these elements are greatly exaggerated in my opinion.
Gothitelle is indeed a heavily matchup reliant mon by itself, failing to do anything useful against most HO's and being capable of destroying stall and balance teams that don't properly prepare for it. However, what people aren't really bringing up is that the person using Goth needs to deal with the matchup reliance in their teambuilding, usually by overcompensating on the other end.
I remember when writing the Goth analysis that CKW wrote that he believed Goth would still be a cteam mon like it was before SM if it wasn't for LO Marshadow being introduced as a powerful anti-offense tool around the same time it got popular (probably true when it was just introduced and many existing offenses just lost to it). Goth lends no defensive support whatsoever to a team, so when building with it it feels impossible to justify adding more stallbreakers given the need to cram anti-offense mons to compensate while maintaining some form of a defensive backbone. Ubers is pretty offensive to begin with, too, so if you build this type of win-at-MU team you won't get past the 1400 ladder. Because of this, Goth carries a fairly heavy burden against stall and balance teams, as many Goth teams become simply unable to break a stall core if Goth takes enough chip, so the stall matchup isn't even all that advantageous.
If given advance notice that you're facing a stall team, Goth is completely broken. In a real Goth team that needs to prepare for a generic matchup, you won't be that much better off against a defensive team.
The idea that Goth is uncompetitively easy to use is just wrong imo. Yes, once you have it out against an Arceus-Water or whatever killing it doesn't require thought. However, Goth can't take a hit coming in against most of what it traps, and is too slow to really get a chance to rest after a misplay. Aside from getting it in through a double-switch, which is risky and requires skilled play, you're forced to build with a clunky mon like magearna/scizor/scarf ygod for voltswitch/uturn support. Even revenge killing doesn't get you a free switch for it, because its targets are passive mons that don't really kill anything, and in the rare situations that they do, a semi-skilled opponent would switch them out the last turn they kill something with toxic or weigh the pros and cons before using the coverage move. Gothitelle is perhaps most difficult as a teambuilding challenge (which is also a way skill factors into the game), but in actual gameplay it still requires good predictions and careful play to use properly. Even the least consequential errors with Goth would still give the opponent a completely free turn with the wallbreaker that scares it out, which can be devastating in many situations.
I would also disagree that Goth adds nothing to the tier. I sometimes see it as reminiscent of the spinblocking mechanic of old gens due to how it makes people hesitate to defog, which is a neat option in a gen where everything gets Defog.
This is not to say that Goth should stay in the tier, but I struggle to see that the arguments used to ban it under the current philosophy are convincing. If anything, its an interesting reason to at least ponder other tiering philosophies.
ESM's post on this thread is honestly the post I've agreed with most in my entire time in the ubers forum. The tier is overcrowded, and if Goth were banned as the start of a systematic attempt to make the tier less crowded by tackling the few elements that require their own isolated stops, such as GeoXern, the base experience of playing the tier as a distinctly ubers tier would remain, but it would allow for far more creative teambuilding than we have now.
In the original thread on the new tiering philosophy, Orch advocated for a tiering system based on fun, which if nothing else feels a lot more like the real issue people have with Goth. It's a pretty valid reason, too: it's probably the least noob-friendly element of the tier, and might keep the tier from growing as a result, not to mention this is meant to be a game and if people hate playing against Goth, that should be valid.
However, if the question is whether Goth is uncompetitive, I don't really think a ban is justified.