"home built auth system" is bound to have "random SSO issues". You fix them, that's how things mature.
Yep, it’s just a drag. It’s not our core product value so any effort we put into it is a drag.
I'm guessing they simply didnt want to spend the time and money doing that
Supabase's auth is MIT licensed and OSS, is it not?
https://github.com/supabase/auth/blob/master/LICENSE