They keep getting stick drift at insane rates (anecdotal evidence), which sony ensures is a great pain to get fixed, assuming you’re in warranty.
Ive just replaced one stick in my friends ds5 with the hall effect type, which should outlast the rest of the controller and cost £1.50 (which I’m sure would be less wholesale).
You’re still rubbing a conductor against a resistor - that will wear out due to physical contact no matter what.
Calibration would be a good.