Earlier quoted context omitted.
The device is not mandated to be a phone. A hardware passkey is also an option. You carry the keys to your home everywhere, don’t you? And you take good care of them? Why would carrying a webauthn-compliant hardware key be any different?
If you lose your keys, you can replace them pretty easily. The mental model for doing so is pretty simple and doesn't require contacting tens or hundreds of websites. I'm pretty skeptical that passkeys are going to yield much benefit. Websites will still have to maintain a "recovery" flow for the reason above and this is already the weakest link a lot of the time.
Under this model, new authentication pretty much should always leaves a paper trail, while passkey login, could be more like the "remember me" cookie from the old days.
Sorry for the tangent, but has anyone ever heard anything about cross-device cookie synchronization?