Right, and if you don't want a single trackable identity, which lots of people don't, a nice modern phone can also WebAuthn using say a fingerprint reader† and so you can have one step sign in (tap sensor, sign in) that way with the resulting "identity" living only on that one site.

† You might be thinking wait, we don't want to be trackable. WebAuthn doesn't have any way of sending fingerprints to anywhere, the phone is using the biometrics to make this not work for bag snatcher, or for the guy snooping your desk while you go get a coffee.