ActivityPub could be the future
I like Mastodon and ActivityPub, and I like that they're seeing relatively broad adoption. That said, I'm not hopeful for the future. If it ever actually sees broad adoption beyond the tech community, all Facebook or whatever comes next has to do is incorporate ActivityPub posts into Facebook, perhaps even send back Facebook comments to those posts, but not publish Facebook-originated content. At that point, you can either be on Facebook and follow all your Facebook and ActivityPub friends, or use Mastodon or whatever and only follow your ActivityPub friends.And even if Facebook does not do that, if a particular ActivityPub client becomes wildly popular, it could do the same, much like how Google Talk started out as interoperable with XMPP, only to ditch it when Google Talk was popular.