It exists for US citizens at least: login.gov (https://developers.login.gov/oidc/getting-started/)

It has it's pros and cons, maybe more pros if you factor in that the biggest issue isn't authentication really, it's the fact that all of these private companies accrue everyone's sensitive info, which can be abused by any actor, private or public. If data were kept on the client side, and synced to other machines through P2P like WebRTC, then maybe this wouldn't be such a big deal.