I genuinely don't believe Garganacl is currently in a state where it requires action and I definitely don't think it will need action after home.
Garganacl is extremely weak to trick, and there are so many good trick users in the meta that are viable rn, (rotom, gholdengo, greninja, meowscarada even). Some Covert Cloak mons are also completely able to counter it, Amoonguss is in my opinion the best counter in the meta and is also a great defensive option anyway.
Tera makes it difficult to deal with, but mons like Amoonguss deal with it's two most common tera types (water, fairy) extremely effectively. I think flying is probably the best tera type right now, it makes it frustrating for common opposing checks, (tusk, amoonguss etc). But no matter the tera garganacl loses if it gets tricked, pretty much.
You Tera ground and block a rotom-w switch in, you PP stall their hydro pumps then curse to +6 and salt cure it. It can choose its Tera to choose what mons to turn into free turns.
idk who is hard switching rotom-wash into garganacl LOL, but to address the rest of that post, Block tera type is just matchup fishing. It kind of reminds me of Volcarona, Block Garganacl Ground Tera for example is an insane matchup fish mon.
As previously mentioned Block Garganacl also needs to give up a valuable move slot. take this moveset for example:
- Salt Cure
- Earthquake
- Block
- Recover
to run curse you need to get rid of earthquake or recover, and you're never removing recover.
IMO block garganacl is sort of a matchup fish gimmick, stealth rock and ironpress are both very reliable sets, but both are very easily dented by trick, sub users, and covert cloak. It's definitely annoying, but not at all unmanageable and I've personally never had a problem dealing with any garganacl set. I do agree it restricts team building options however, but I don't think running a trick mon, slapping sub on something, or running covert cloak on amoonguss is nearly as restricting as for example Chien-Pao, where it had 3 or 4 reliable checks, all of which would have been nearly zero usage in OU without Pao.
In conclusion, I don't think Garganacl is as bad as people would like to think right now, and I think it's a nice splashable mon that is able to force forward progress and I generally think that it's ok in this meta.