As I see it, it has been replaced by OAuth, which is created for a different purpose but works just as well for login and authentication.
OAuth 2.0 is an authorization framework, not an authentication protocol. OAuth 2.0 can be used for a lot of cool tasks, one of which is person authentication.
OpenID Connect is a “profile” of OAuth 2.0 specifically designed for attribute release and authentication.
For more info, see our blog: OAuth vs SAML vs OpenID Connect. [1]
[1] https://www.gluu.org/resources/documents/articles/oauth-vs-s...
> OpenID has been replaced by OpenID Connect
Replaced != compatible.
Also, "traditional OpenID" is very ambiguous phrasing... are you referring to OpenID 1? OpenID 2? or OpenID Connect?
In fact, the few websites which supported OpenID allowed to use custom providers while OAuth mostly limited to handful of social media providers. So OpenID was a way to decentralize the web and prevent password reuse while OAuth is a strategy by large Social Media corporations to increase your dependence on their brand.
In the end they both might be able to authenticate and to prevent password reusage to some extend, but their motivations and implications are very different.