I'm predicting that eventually Google will start deranking HTTP 1.1 websites.
You do not see how lack of built-in authentication increases complexity of implementing your own website as opposed to "outsourcing" stuff to Gmail, Google Docs and so on? You don't see the zillion "sign in with Google" buttons all over the web? You don't see how cookies are abused for tracking, which benefits Google orders of magnitude more than it would a smaller company?
It's in no way easier than adding keycloak authentication for example, which is another (selfhosted) external authentication solution.
Social auth isnt there to make authentication easier for the website owner. He still has to do everything he'd have to do if he didn't use it.
It's there for the users, do they don't need to remember a bazillion passwords
Google, a multi-billion dollar corporation that owns most of the browser and search market share, a company that dictates the next transport-layer protocol we will use - this company struggles to design a session-handling mechanism that would out-compete an ugly hack that Netscape ductaped to HTTP in mid-90s.
Cookies were a hack to add sessions on top of http.
[1] https://varnish-cache.org/docs/trunk/phk/http20.html#beating...
[1] https://varnish-cache.org/docs/trunk/phk/http20.html#beating...