This article in the IEEE Spectrum is a good explanation of the overall of the new social networks for those of you who've so far missed what Mastodon, Fediverse, ActivityPub et al are about, and what WordPress, Medium, Mozilla, Flipboard, Tumblr, Flickr and a bunch of other web stalwarts are up to. And, yes, even Meta is hedging their bets with a new project, exactly as you'd expect them to.
spectrum.ieee.org/mastodon-soc