when my skin gets roughed up - makes the print reader not wirk and I have to use my PIN.

When I had my work iPhone, it might do that, but it would tell me to try again.
There was a setting to tell how many failed fingerprints to require PIN. I gave that phone back when I retired.
I can't find any setting like on the iPhone.
Am I missing something or is that not a feature?

Not sure you'd want to change how that works.

Or are you saying sometimes it doesn't even give you the option to use fingerprint once, and instead goes straight to a PIN authorization and you wonder what causes that?

One try, use PIN. No way to increase # of tries.

Every now and then you need to use a PIN to unlock the phone when you have the biometrics enabled.
This is part of the security system, which you have no control over.

If the phone is having problems reading your fingerprints, then the PIN is the obvious fall-back. Not sure how many failed attempts it takes to get to the PIN screen. (I have all the biometrics disabled on my phone.)