I'd just like to interject for one moment. What you're referring to as Mastodon, is in fact, a decentralised network of nodes, or as I've recently taken to calling it, the fediverse. Mastodon is not a social network unto itself, but rather another frontend of a fully functioning federation made useful by the ActivityPub protocol, other nodes and communication between those comprising a full social network as defined by the World Wide Web Consortium.
Ich mag auch freie software
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!