I'd just like to interject for a moment. What you’re referring to as Mastodon, is in fact, GNU/Mastodon, or as I’ve recently taken to calling it, GNU plus Mastodon.
Mastodon is not a social network unto itself, but rather another free component of a fully functioning GNU system made useful by the GNU Social platform, federation and the vital ostatus standard comprising a full instance.
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!