After spending six weeks with the iPhone X, I’ve found a lot to like in the device; it’s the most advanced smartphone I’ve ever used. Apple did a masterful job of designing out the iPhone’s iconic Home button– I don’t miss it at all–but I do miss the Touch ID fingerprint sensor that was once co-located with it.

When the X is sitting flat on the desk, its Face ID facial recognition system can’t see my face to authenticate me and unlock the phone. I can no longer just rest my finger on the Home button to unlock it. I have to pick up the phone and point it at my face to authenticate. No big deal? Well, on about the 10th time in one day it starts to seem like a big deal.

And Apple Pay mobile payments have become harder on the iPhone X. It’s no longer just one smooth movement of pointing the phone at the payment terminal with my thumb on the fingerprint sensor. Now it’s: (1) double-click side button, (2) point phone at face, then (3) put phone near terminal.

Of course this could all have been avoided if Apple had put both a fingerprint sensor and a facial recognition system in the iPhone X. Multiple authentication options are nothing new: older iPhones had them (fingerprint, pin code), and Samsung Galaxy phones provide a fingerprint scanner, facial recognition, and iris scanning. So why not just add one more in the iPhone X? It’s possible one mode of authentication just can’t cover all use cases.

Therein lies a tale about the iPhone X, which went all-in on Face ID only after Apple experimented with a new form of Touch ID and found it wanting. But even if Apple shifts entirely to facial recognition, other phone makers may offer a next-generation flavor of fingerprint scanning that matches some of Face ID’s virtues and lacks its downsides.

How Touch ID Died

Apple planned for the 10th Anniversary iPhone for a long time. The Phone of the Future had to be pretty much all display on its front, so Apple was hell-bent on putting an “edge-to-edge” OLED screen on the iPhone X. With no more “chin” space at the bottom of the phone, the Touch ID button was out. But a source with knowledge of the iPhone X development process told me Apple still worked for months to integrate a fingerprint sensor directly into the device’s display.

By last spring, however, it become clear that the in-display fingerprint sensor wasn’t going to work. The sensors in the prototype iPhone X’s were generating too many false negatives; that is, keeping legitimate users out of their phones.