Sorry, I still don't see the improvement here, doesn't that already happen using chrome for example, or Touch ID with 1password? (I think IOS has that too)
That's correct, but 1Password stores a static secret (the password) and this may be re-used by less security-minded folks as you probably know. WebAuthn servers only store a public key which is useless in case the server gets compromised. WebAuthn also is phsihing proof by having browsers verify the domain the credentials are used for.
