The only choices being MS or Google for auth, both with trigger happy defence mechanisms, is kind of annoying though.
To take the contrarian stance though: SSO not being paid is kinda nice, and not having yet another password for something is nice. —- double and: then not being able to leak a password or handle 2FA, instead focusing on their actual product.
Might mean a little more work to help reimplement GH features in the platform of choice. Not everyone will leave.
But it'll be great for the diversity of the internet.