The short answer is that you can lose a biometric but still be you. So a biometric is not a username. Also, the biometric does not actually replace a service p

The short answer is that you can lose a biometric but still be you. So a biometric is not a username. Also, the biometric does not actually replace a service password in this instance, it just helps authenticate you locally to a device. The key on the device is what is actually replacing your password. Depending on the device or settings you choose, you don’t need to use biometrics at all if you don’t want to.