The communities I have been apart of over the years are dependant on my interests at the time and whatever connections I make through already pre-established relationships, that being said, for a few years one would've been Roblox, then Star Wars, then a bunch of other slopshit.
I've also sampled a lot of different image boards, forums and social medias in the past and I honestly prefer forums and imageboards more than the streamline social media format.
Say what you want about Twitter, but I don't like the way it's structure or how you're supposed to communicate with others, where you're sort of left to your own devices and an algorithm picks random things for you to engage with, because you're not engaging with the person or people directly, you're just engaging with their posts and posts/re-posts that they're sharing. It's like a void you scream into awaiting the echo chamber's reply. It's also much more instant and a rapidfire stream of posts and threads and discussions and what not, with shorter more brief replies, which leads to unnuanced casual surface level discussions that don't really amount to anything which is by design.
Look at a random thread from some random forum from over a decade ago and compare it to your typical conversations had in threads on Twitter or ChinkTok. It's night and day.