Lemmy is seen as another Reddit, that's why people are coming over to use it as a potential alternative.

I'm also not convinced that the community would scatter entirely. Things might be scattering now, but this is more like the entire Earth being blown up for some space highway.

Whereas previously on Reddit, the community might splinter, with some parts going off to make their own subreddits, effectively moving to a new bar. It's happened before, with multiple subs.

/r/anime_titties was created due to issues with how /r/worldnews was moderated, /r/curatedtumblr was created due to issues with bots and inactive moderation on /r/tumblr, so on.

But moving subreddits is a far cry from moving to a whole other site, with its own communities, quirks, and issues, where they might be losing out on creature comforts, and the identity that they've built up on Reddit.