Oh I think it definitely did damage, just not enough to kill such a massive platform overnight. Twitter has lost a significant amount of users while other social networks grew or held steady, and the cultural impact seems to have waned a lot.

I've never been a regular user of Twitter, pre or post elon era, but a lot of people I follow in other ways used to be very active on there and discussions would often spill over into other venues. That still happens a bit, but much less than before.

Its hard to say. Reddit is still a shit show, but I still peer into niche communities you won't find anywhere else on the internet.

Discord is even more niche than that. There's tons of IRC esque group chats of that's what you need. But a community: not so easy to replace.