I'm not OP, but I seem to naturally hold my iPhone closer to my face than the distance at which FaceID works. Either that, or the system just doesn't like my face.

FaceID works so poorly that I actually disabled it for unlocking my phone. At least when I use a passcode, I can set a grace period of one hour before the passcode is required again. If you turn on FaceID, it's always required as soon as you lock your phone.

I have an iPhone 13 Mini fwiw.

Brushing my teeth? Can't unlock my phone.

Fresh out of the shower? Can't unlock my phone.

Phone too close? Can't unlock my phone.

Want to quickly unlock my phone while it's laying on my desk? Can't, gotta lift it, point it towards my face, then lay it back where it was.

I dunno, I have a bit of relief when I can just unlock my iPad with my finger.

When I am wearing a mask (for health reasons) it won't unlock.

I too miss the finger print unlocking.

But fingerprint unlocking didn’t work with wet fingers, like outside on a rainy day. I find that face unlocking fails less often than fingerprint unlocking ever did. (Though outside on a sunny day can be challenging.)

That’s why I want both

The problem with both (as much as I want it too) is that it reduces security because the chance of a false positive (falsely identifying you as the owner) for either/or is always higher than the chance for a false positive for each individually

I guess when I wear sunglasses, or my CPAP, or am simply not in a position to look directly at the screen dead-on (such as when driving in the car when it's on its mount, or when I'm packing groceries and need to pay), or when I just don't want to look like a goofball staring dead-on at my phone screen, TouchID worked 100% of the time and was minimally inconvenient.

If I went kayaking every day, or just generally had wet hands a lot of the time, I could see how that could get annoying (although hand towels exist...). I wear my CPAP every night though, and didn't always feel like taking it off just to unlock my phone.

FYI, when Apple made FaceID tolerate face masks during the pandemic (probably for the same reasons it was annoying with a CPAP), they actually made it less secure (because there is no circumstance under which giving less information but expecting the same level of security will hold)