at the moment the public interface is just google.auth.default() and load_credentials_from_file, but if we have a data dictionary already due to it being loaded from a non file source it would be nice to pass it directly to load_credentials_from_info https://github.com/googleapis/google-auth-library-python/blob/main/google/auth/_default.py#L133

the load from file function is just a super thin wrapper to load from info.

afaics load_credentials_from_info is the most compatible across all the auth forms that gcp supports. (user default app, service account, external).