Doesn’t the phone have to be unlocked? The watch authenticates one time when you put it on (and unauthenticates when you take it off), so you can securely pay for things via a double click of a button then tap, vs having to unlock the phone with your face first or enter a pin or whatever. If someone steals your watch, they can’t steal your money unless they some how can cut off your wrist without triggering an unauthentication.