MitID (national provider login) in Denmark, is about 2 layers of oidc in of itself (normal oidc and an oauth2). Plus whatever the consumers already have, which is often 1 or 2 as well. They're often used as a layer of abstraction which is a gross misuse of the technology.

As I mentioned previously using it for social logins by itself, is fine in most situations as they're quite mature. And IMO the best and probably intended use case of the technology and there it works quite well.