Honestly, I find it quite reliable, maybe not as reliable as its competitors, but I feel good about it, and I often use my fingerprint instead of unlocking with my face.

Yes, it sometimes works, but not as well as with an iPhone.

Do not use them !

I don't do that in principle. I had an incident with the police (road traffic accident). They confiscated the mobile to see if I was on it while driving. They held it in front of my face to be able to open it. Couldn't because there was no Face ID. It's actually only allowed by court order, but they do it anyway.

It works so well for me that I hadn't even thought about it before. It was only when I saw the question that I tried out this functionality in more detail. When I hold the device so that the front camera is facing my face, the device opens reliably.

I don't know because I bought the device for another person, but I was able to test facial recognition on a much cheaper XCover 5 and it worked fine there.

Then you are doing something wrong. It works perfectly for me. With or without glasses doesn't matter.