Infinite growth is not a good thing, numbers rise and fall just let it do it's own thing. That being said, maybe if the Lemmy instances would stop defederating like children snatching toys from one another at a daycare it would get more engagement.
Read the comments thread of ANY of the "we defederated from" posts and it's always the same "They were annoying tankies" shit. It isn't a matter of abusive users, they have tools for that. They just want to allow fash shit to fester unopposed by the people capable of disarming it.
Just look at any instance that has hexbear and lemmygrad blocked. Their culture is already starting to decay into becoming reddit nazi bars.