I do not known why OIDC has so many bad comments here. At my $company we are using Keycloak for multi-realm (multi-tenant) authentication of users and clients (applications). Yes, the learning curve is long for OIDC and even longer for Keycloak. The FreeMaker Template Engine is awful compared to Twig. Updates of Keycloak can break something, so better have proper test/stagging environment. But this is the tax for not implement something, that is not in core domain of organization.
OIDC solves problems for OAuth2 like "every Identity Provider has different endpoints" with OpenID Connect Discovery (/.well-known/openid-configuration).
OIDC solves problems for OAuth2 like "every Identity Provider has different endpoints" with OpenID Connect Discovery (/.well-known/openid-configuration).