Apple SVP Federighi: Touch ID was not intended for multiple users

One difference between Touch ID and Face ID (besides the obvious fact that one is a fingerprint sensor and the other is a facial recognition system) is that the former inadvertently supports multiple users, while the latter does not. For the convenience of Touch ID users, multiple fingerprints can be registered so that you can touch the fingerprint button from different angles. This also can be used to allow more than one person to use the same Touch ID enabled iPhone model.

While there are some Apple iPhone X users who would have preferred Apple to offer Face ID support for multiple users ...