I’ll put in a strong vote for www.hello.coop, a solution that I use on my Discourse forums that allows users to choose whichever type of login they’d like, from phone number to email to social logins and maybe even passkey.
And once someone has a Hellō account, they can login to any Discourse site that uses it.
Maybe the only difference would be that each of my Discourse communities would still require the user to answer community-specific questions when initially signing in.
The founder is Dick Hardt, who has done a lot of work on the OIDC spec, I believe.
Anyways, maybe something to explore. I’d love to answer any questions and I know Dick and I’m sure he would as well.