I STRONGLY recommend just going out looking for whatever forums you can find that are still active.

I've actually been going out of my way to look up new forums to use since the Reddit API controversy. Finding them can sometimes be a pain in the ass because search engines suck nowadays, but I've found a few I hang around on. I spend way more time on them than I do Lemmy.

I actually just launched a PHPBB forum for specific interests in regards to the indie web, building websites, and sharing random banter (among a few other things). I find Reddit and Lemmy to be useful for seeing what's going on in the world overall, and Discord has mostly just been annoying ever since its launch, and forums seem like a good answer to recreating actual communities. And if there are more people who feel this way, maybe they'll make a comeback (because they definitely haven't just started to be affected by corporations attempting to centralize everyone to one thing).