That is not the world which passkey advocates envision. In the case of those services you mention, passkeys are nothing but convenience; they provide no extra security. In the world passkey advocates envision, passkeys improve security, meaning the removal of password authentication options.
I've already been temporarily locked out by one such service, because a Firefox update made the passkeys I store in Bitwarden inaccessible (Firefox would pop up a macOS Touch ID modal rather than the Bitwarden passkey). That is the world which passkey advocates want, because it "improves security".