Is there a reason why all the services, that use the ActivityPub protocol don’t have a unified API?
None of the mastodon apps allow me to log in with a lemmy/kbin account.
Also none of the lemmy apps allow me to log in with a kbin account.
Even though kbin has both mastodon (microblogging) and lemmy (threads, communities) functionality.
Also, Pixelfed recently introduced “login with Mastodon”, but all it really does is just create a new user on it’s instance and copy over the mastodon followers and profile info.
Why can’t we just have one account to rule them all?
It cannot work as stated because there could be another @adonis accounts in other instances and the only way to prevent that would be to centralize all the signups which goes against the whole idea of decentralization. That’s why the user must be @[email protected] as it is shown now.
Regarding the OAuth/JWT, again… not an expert, but what I understand is that that kind of integration is much stronger than the current system. AFAIK, it could work as you say, but that would make things much more complex for the servers; you usually provide OAuth authentication for a few services, I don’t know how well that scales with … hundreds / thousands (?) of authentication provders. But, who knows, maybe in the future it’s implemented in one way or another.
We should take into account that this technology is fairly new and people are still building on it.