I think the self-hosting bit is a bit flawed, its almost entirely based on opinion.
For example, I'd have taken a lot of points from email as its all too easy to get blacklisted for doing everything right, and setting up everything is a pain. Cory Doctorow (Author and popular blogger) got on a spam-blocklist for self-hosting his newsletter, and it was an effort for him to get himself off it. It would be impossible for an average joe to get off a blocklist.
You can self-host old versions of reddit, I'd have given it a few points.
Self hosting a PDS is pretty popular, but the average PDS has less users than mastodon instances.
Maybe not bluesky itself, but there is lots of atproto AppViews (essentially clients) which do stuff. Would you classify frontpage.fyi as a client?
There is clients for bluesky itself anyway, graysky, deck[.]blue, AppViewLite, the official apps, deer[.]social gander[.]social tapestry, surf, phoenix (made by the people who made ivory), skeets (real app), bluejeans, off the top of my head.
I think the content share part doesn't really apply to bluesky since everything is portable, so if bsky disappeared, all content would still exist and be referenceable. Unlike AP based stuff, where everything is tied to its host server.
Bluesky would work better for that, since everything would be on the AppView. Hosting multiple appviews would be intensive on the relays, but different ones could keep content for different amounts of time.
I think AP works better when you don't need or want all the information to be available at once.
Decentralisation is not black and white, and depends on your defintion of the word.At this point, the problem is that everyone is on bluesky's servers. There is little technical problems.
There's a good few more PDSes than I thought. There's a few with open signups. Though, for relays the situation is a bit more bleak.I'm sure it will improve in future, there is a lot of orgs planning on setting up AT infrastructure.
Sam Altman makes money from people believing this.