I get that it is not a ubiquitous solution, but after my experiences on mastodon.social and others, I'm really starting to wonder just how genuine the sentiment behind "it's hard to sign up" is. It's not that hard at all - I have found it a lot easier than doing something like creating a modern facebook or google account for instance.
The new UI and general idea of federation takes some figuring out, but the high level experience of "see a post, click, read comments, comment" isn't any different from Hackernews.