I like SAML because it does not involve http requests to fetch user profile (unless I'm missing something and OIDC allows that too). The whole user profile comes with the signed or encrypted payload.

As a result you can have identity provider sitting in an unreachable / private network.

Or.. Your identity provider doesn't even have to be a network service at all. We have some integration tests around systems using SAML for authentication. SAML authentication statements in test environments are generated by the test suite and fed to SPs via Selenium controlled browser.