I remember a viral post on Twitter from someone listing nothing but complaints about Mastodon/federation which was written after the big furry instance, snouts.online, imploded. This was a few years ago. I’ll admit it made me skeptical about the fediverse, but after actually trying it out for myself it’s not as bad as that thread made out. Might be that that thread is still in the back of people’s minds when they consider twit alternatives.