are we sure it's not just kydex rubbing off on the gun?
I carried my first glock in a kydex holster from DeSantis for almost 2 years straight before it ever started to show even the faintest signs of holster wear. Same thing, only on the 'inside' left side of the gun. It was from reholstering the gun I believe.
I've got holsters from Raven Concealment, Bravo Company, Haley, T.Rex Arms, and Opsec now. None of them have caused holster wear on the gun that quickly.
As an example, here's a Glock 19 gen4 I picked up about two months ago. Lots of holstering and draws since then and maybe only like 500rds.
First picture is right out of my holster as I type this. Second picture is after rubbing off a bunch of the 'scrapes' with spit on my shirt. It still looks like there's "highlights" that appear to be wear, but it's no where near through the finish. Some lube on it will help even out the color too.
But also to reiterate what other people said: if you carry a gun, I don't care the gun and holster combo, you're going to get holster wear. Look at is as a point of pride. When I see an obvious defensive pistol with no discernible wear on it I think "oh well, there's someone who doesn't use their gun." Just like when I see a sport bike with 1" strips of unused tire on the edges of their tires.