Define less - this is an emotional not a logical distinction
There is a case that Kydex will concentrate the wear more and leather will spread it around.
A poorly fit Kydex will wear more than a well fit Kydex. A Kydex full of sand will wear more than a Kydex carefully kept clean and free of grit.
A loose leather holster lined with soft leather and allowed to hold lots of grit will wear much more finish than a properly fitted tight fitting leather holster carefully kept clean and discarded when after many years it begins to be too loose.
Many people frex in IDPA think Kydex as a class is a little faster in otherwise comparable holsters. Of course an Ernie Hill competition rig will tend to be faster than an inside the waistband in Kydex and fancy retention schemes as gripping the trigger guard will be affected by checkering on the trigger guard so it's hard to make everything else the same.
For my money proper fit is more important than the material and I choose leather.
