The largest issue with the fediverse is that so few people seem to understand what it actually is. Even this paper talks about Bluesky, Mastodon, and Threads as

The largest issue with the fediverse is that so few people seem to understand what it actually is. Even this paper talks about Bluesky, Mastodon, and Threads as if they’re mutually independent. They kind of are, but that misses the point of what the fediverse is meant to be. I am part of a public mastodon server and the academic migration was like watching people discover what it was like to “surf the web” again. This paper generally rings true to my experience. In my view, this particular failure of fediverse adoption was because there was a large group of people who were using immature technology for the wrong reasons, and the friction of their incorrect mental models outlasted their righteous indignation about Twitter/X. If you haven’t taken a gander through the fediverse yet, give it a try. It’s beautiful and weird the way the internet was in the days of geocities. But it can take some digging - my best results have been in finding people who are running custom, non-mastodon servers.