It's a little sad, but OpenID implementations ended up being rather one sided. Everyone wanted to be an OpenID identity provider, but fewer wanted to be on the consumer side. For OpenID to succeed that relationship needs to change.

There was simply no benefit for the larger sites to access OpenID as an authentication mechanism. Perhaps the EUs General Data Protection Regulation can change that to some extend for smaller sites that wish to store almost nothing about the users, while still authenticating them.