I haven't used Cognito or Google's one, but Azure AD B2C is a complete mess. Or it was 3 years ago. A disaster of poor configuration options, and poor documentation, and even when we spoke to internal Azure engineers they said the same.
Stick with something like Auth0, or self-host Keycloak. Don't use the Azure one if you can at all avoid it, at least for B2C applications.
I truly believe this is why email-based logins have become quite popular. You delegate the security of the authentication to the client (whether they’re a B2B client or B2C doesn’t make much of a difference), you don’t need to have 2FA, password reset flows, etc.
Still doesn’t support FIDO security keys for any accounts including admins.
I wish there were two versions of the UI:
1) the current "God mode" with hundreds of services and nested pages for cloud uber natives that grok all that, and
2) a simplfied UI for simple devs like me. There could be a few types of the simplified UI, depending on what you do (mobile dev, ML researcher, AI engineer, web dev, etc.).
Currently, I spend way too much time scrolling and navigating between different pages to set up or troubleshoot basic things.