I'm sure that's a huge help for people who like to check their notifications or other things on their phone while it's sitting on the desk without picking it up. There are tons of situation where your face is not in front of the phone yet you would still like to unlock it without contorting you or it, and how well face I'd work or not has nothing to do with it.
Yes, that's one of the occasions where I have noticed it not working well. I guess it just depends on how often you do that and how annoying you find it to have to lift the phone up a bit. Not a big deal for me.
Or having to remove your sunglasses, or when you have a face mask on, or when the ambient sunlight/IR is too high for the sensor to read the tracking dots it projects on your face.
FaceID introduced a huge swath of new failure modes while simultaneously reducing security. Not acceptable.
FaceID works totally fine with your sunglasses on and in bright light...
It does fail if you have a mask on, if you have goggles covering half your face, or if you have a helmet that covers your face... but to me that is all completely understandable.
And also something that you can partially alleviate with alternative appearances in the FaceID settings, depending on how much of your face you're covering.
Yes, I will admit that it's not great with a face mask. But then that wasn't really an issue until a few weeks ago. Never had problems with glasses or too much sunlight but that might just be a perk of living in a country that's not particularly sunny.