These days most every website has "log in with Google", "log in with Apple", "log in with Microsoft", etc which sort-of addresses the issue (ironically to this comment, "log in with GitHub" is also pretty common).

A more generic federated identity system that everyone could use/operate would of course be 1000% better. But slightly orthogonal to forge/no forge.

I don't think it really addresses the issue because it still requires an account at one of the predetermined identity providers. With email I just need a domain and I can self host the rest if I really cared to.

It would be so much nicer if there was a federated way where I the user could specify any OAuth identity provider (even if it was e.g. a self hosted one) rather than the predetermined list dictated by the relying party.

Funnily enough someone recently asked me if I could comment on a Product Hunt post and I was unable to do so since they only allow sign in with Google, Twitter, Facebook, Apple or Linked in; I have none of these accounts and would rather not create any of them. Oh well.

I refuse to use those, because that means now my ability to log into this website is tied to my ability to log into the identity provider's website. I'd rather maintain control over that myself.