I’ve recently tried to use peertube and I think it could improve a lot if it showed all the content in all instances. But instead you have to look around many instances to try and find something you like. Then there’s other thing, it can’t suggest content if it doesn’t know what you like and without sharing the data between the instances it doesn’t know anything about anyone. If the user data was encrypted and shared between all sites, when you log in it could use the now decrypted user data to suggest content. Or maybe it can share the data with third parties, I don’t really know.
Personally, I feel like an approach that separates the user identity/account (something like OpenID) from the content server would make more sense for public content and from the client/view/UI/portal used by the end-user to access to the content. Then use standards for any particular server-to-server communication. Much like how blogs can do backtracking between blogs and so.
To me, federation between private servers the way mastodon does it only makes sense for private communication like XMPP or Matrix… but the minute you are publicly posting content in the internet it makes no sense to have servers mirror the content from others just so people can access that content from one server in the next… why not just directly obtain the content from the server it’s from and load it in your client/UI of choice? without having to depend on the server you have an account on hosting it? it creates a dependency between the user and the server that hosts your account and makes it so you might end up having to create multiple accounts in different servers, and at that point it’s not much different from centralized services.