I would imagine that different people use their phones differently. At work I use my phone mostly for picture documentation which I use frequently but with a shortcut. So I don’t have to unlock my phone all the time and when I do I’m usually wearing gloves so I’ll use the pin instead of the fingerprint reader anyway. As a result very rarely am I using the phone when my fingers are wet, covered in grease or oil, etc. Cuts and burns do have a detrimental effect on the accuracy of my fingerprint sensor but they also don’t happen enough on my fingertips to be a serious problem for me. As a result, I’m not having a lot of the same problems frequently that other users who use their phones under these circumstances do.