Let's talk federated social media

I've been on mastodon for a bit now and I'm very much enjoying it. There's a few other options out there, with a variety of goals (pleroma/mastodon for microblogging, pixelfed for photos, hubzilla/diaspora for a more complete package).

I had some questions in mind (but feel free to discuss anything vaguely related): how do you think federated social media is doing? Do you use it? Do you try to get others to use it? What do you think some barriers to widespread adoptions would be?