I "tried" to use XMPP/Jabber in its heyday, but in my experience (& memory) it never got to the point to have a "critical mass" of community (I felt to be part of / want to be part of).
Fediverse/Lemmy has this critical mass at least since some weeks now - unless too many of those users decide to leave for another place, I'm happy here no matter what other things get hyped in a given week.
Back in Jabber's day, I would have liked to see it develop some communities as they did - and still do! - exist on IRC, but that simply never happened (with one I would both be interested in and could find).
Is it (more) about Meta themselves, or rather about individual users, though?