Authentication and Authorization options for building SaaS

Hi everyone,

I have build about 3 micro SaaS applications so far and have not yet found a seamless & cost-effective authentication and authorization with functionalities like Email login, Google login, Groups, Roles and Permissions etc.
I have used Keycloak and Auth0 so far and still end up either paying a hefty amount or managing lots of things at my end.
Then there is the need to integrate with email APIs for the signup/forgot pass flow.
Things become more complex if you want to enable MFA.

What are some recommendations? How are you guys solving this today?

Thank you