Apple says that it abandoned all work on an embedded Touch ID sensor as soon as it saw how good Face ID was. Some skeptics wondered whether the real reason might have been that a fingerprint reader embedded into the screen simply didn’t work well, but tests on a rival system appear to show that the option would have been viable.
I am really starting to think people are not aware just how far in advance decisions need to be made. The under screen fingerprint tech may work fine NOW, but the iPhone X was released months ago, and the final features would have been locked in way before that.
This looks destined to be a staple of Android phones and is highly unlikely it to return to Apples handsets, although there is no reason it couldn’t. Biometric authentications could be from any number of places, so could be on the iPhone SE for instance and function exactly as before - but Apple like uniformity and are more likely to start putting Face ID into more things.