Right now it’s possible to add integration with external authentication though a couple of work arounds at the moment, I specifically use a HACS component called header authentication and with the use of OAuth2 Proxy and NGINX Proxy Manager I’ve been able to partially add OpenID OAuth to home assistant but it is far from perfect. I understand this is sort of a niche request but I think this will make authentication for home assistant accounts more robust and personally having one account to access everything in my household would be a major plus.