1. It’s much less reliable. Especially in bed when I get paged at night I almost always have to revert to PIN auth, which is unfortunate when I’m disoriented and seconds count.
2. It’s much slower. With the placement of fingerprint sensors on Pixel phones it is totally natural to have the phone unlocked and open by the time the screen comes into view. With FaceID I don’t even start that process until then, and it’s a several step process: assuming the screen is already on (this works well) I have to look at the phone, wait a moment... then swipe up to actually unlock the phone. Facial recognition aside, the act of swiping up alone is way more work than fingerprinting into a Pixel phone.
3. The thing I like most about FaceID is checking notifications - I can simply look at the screen and Signal messages unlock, etc.
I’m convinced that most of the hate iPhone users have for fingerprint unlock relates to the placement of the sensor, and (never having used an iPhone fingerprint reader this is speculation) maybe it’s speed or reliability. The implementation on Pixel phones was really great and I’ll be sad to see it go.