Why? Facial recognition on an Apple device is 20 times more secure (50k/1 for touch compared to 1M//1 error rate for facial) than the fingerprint (it doesn’t really read fingerprints but reads instead the ridges and valleys of the fat pads below your skin) reader. You actually have to actively look at the 3D infrared facial recognition sensor with your eyes open for it to unlock your device. As such, it can’t be fooled by a picture or even a mask or a 3D sculpture. There is no actual image of your face stored on your device or sent anywhere off device that could be used by any government agency or other facial recognition system. Instead a mathematical one-way hash representation 3D map is recalculated each time you want to unlock your device and compared to a previously stored and updated map in the Secure Enclave on the device. If the newly calculated 3D map is close enough to the stored 3D map, then the device is unlocked, if not, then it rescans. Too many failed scans the device then demands the user’s passcode.
As for the lack of a home button, once you learn the new paradigm of screen motions without the home button, you wonder why you ever needed one and it feels clunky to go back to an iPhone with the home button, and you’ll appreciate the larger screen area.
Mostly because I can pick up the phone or pull it from my pocket while unlocking it in one motion.