I’ve been using fediverse stuff (Mastodon and, most recently, Calckey—I’m just going to use “Mastodon” as shorthand here; purists can bite me) for over a year now and have been doing so full time for about six months, following Elon Musk buying Twitter (since on principle, I decline to give Elon Musk money or attention). This latter part coincided with the “November 2022 influx,” when lots of new people joined Mastodon for similar reasons. A lot of that influx has not stuck around. Everyone is very aware at this point that active user numbers of Mastodon have dropped off a cliff…
I think the issue the Twitter migration had was is very dependent on people with large followings moving, but they are obviously some of the least likely to move for the same reason.
It’s far easier for reddit > fediverse because you just need people willing to post links and have discussions.
In case anyone says “hey that’s about people”, I also deal in absolutes and am a Sith.