Using it isn't the problem, joining it is. Finding a server that has the right combination of
- isn't The Big One (defeats the point)
- has a nice domain (that's your name forever)
- is stable (major downtime or data loss is unacceptable these days)
- is guaranteed to stick around forever (no, migration isn't solved and it will never not suck)
- has rules you agree with and can guarantee you'll follow
- is running the right software (no, "fedi" isn't compatible, you either run Mastodon or things will always be ever so slightly broken)
Some of the points you make are still true, but I think you're a little out of date.
Migration is not solved, but it also doesn't suck - unless you're doing it every week nothing will break, and several people I follow have already done it and it's been just fine.
Stability is also fine - if your server is down for a couple of hours, your timeline will catch up when it comes back online, and likewise your sent posts will stay in a local outbox until they can be sent. That's absolutely no different from email or Jabber or anything else.
"Fedi" is compatible enough that I run my own GoToSocial server, which is technically still beta software, and I haven't experienced any issues following and interacting with anyone on Mastodon, Pixelfed, Pleroma and quite a few other platforms.
Would I recommend it to a non-technical user, someone who wasn't really interested in 'servers' and 'clients' and 'protocols'? Yes, although I'd suggest they just go for The Big One, as you put it. What I would say though is that this is no longer just a technology for Web nerds any longer; it's a very viable alternative to centralized platforms.
- isn't The Big One (defeats the point) - has a nice domain (that's your name forever) - is stable (major downtime or data loss is unacceptable these days) - is guaranteed to stick around forever (no, migration isn't solved and it will never not suck) - has rules you agree with and can guarantee you'll follow - is running the right software (no, "fedi" isn't compatible, you either run Mastodon or things will always be ever so slightly broken)