Yeah, this isn't new. I've been advocating for this since 2018[1], and the PR in question was submitted in November 2022.
The PR isn't dead though. There's some additional discussion[2] on its current state in the issue I linked above. Basically, it needs more people to test the implementation against different sites in the wild.
Hopefully the increasing popularity of passkeys will provide the necessary level of motivation and support to get this over the finish line.
