I’m worried that FaceID is going to suck—and here’s why
Ars Technica 2017-09-12

Enlarge / This right here. This gesture. Doing this 80 times a day sucks. (credit: Apple)
The all-new iPhone X is out, and it's packed with technology. But one thing it's not packed with is a fingerprint sensor. Like many phones in 2017, the iPhone X goes for a nearly all-screen design, which means there's no more room for a front Touch ID sensor. Rather than locate a fingerprint sensor on the back, like many phones have done, Apple chose to do away with Touch ID entirely. Instead, the X is relying only on the new "Face ID" facial recognition feature for biometric security.
Face ID on the iPhone X uses a "TrueDepth" camera setup, which blasts your face with more than 30,000 infrared dots and scans your face in 3D. Apple says this can "recognize you in an instant" and log you into your phone.
None of that matters. Face ID is still going to suck.