I'm not sure. I remember looking at OpenId when it was announced, and the rabbit hole I ran down made me think it was built on webauthn in some fashion, as a set of providers or something.
If that's not the case, that is very unfortunate. I veered into reading the webauthn spec for a bit then and found I largely liked what I found there.
Some complexity from trying to define how to handle people lugging around shareable keys on their phones and similar in the spec, but overall I liked it. I found it all very reasonable.