I've been really happy with my Fobus paddle holster until very recently I've noticed some of the finish wearing off of my Glock.  Do all holster types do this?

pretty much. I've carried in leather and plastic (Serpa, the glock thing you used to get for free, kydex) as well as some Uncle Mike's idiot pouch before I wised up and they all caused "holster wear"

the Uncle Mike's seems to attract all the grit in the land to turn the inside into sandpaper, over time.

They all cause holster wear but I think they wear quickest in this order, leather, kydex then nylon.

That is not exactly correct.

Kydex will wear the high spots FAST. After the surfaces mate the wear stops.  Kydex can also be easily cleaned on the inside to prevent grit buildup.
Adjustable retention kydex holsters will drag a much larger surface area than friction form fit kydex.

Leather will wear the entire surface area slowly, over time the leather will impregnate with oil and grit and basically turn into sandpaper the more it's used. The wear never stops and it's not something easily cleaned out.

Nylon will do the same as leather but most nylon holsters are basically gun buckets so contact with the surface is sporadic at best and wear patterns are all over the place.

Yes;' they will all create holster wear; some like Kydex, will do more than others, like Leather.

they used to make really nice lined leather holsters.

I have one for my S&W M29.  Its as soft as can be inside (no idea what the lining material is but it's sewn into the inside of the leather holster.

No wear in the 2 years I carried it 5 days out of 7, more if I worked some OT.

Now that was a duty holster, on the belt, high ride thumb break, if that means anything these days.

I never looked for a concealment holster made the same way, my off duty gun was my Combat Commander the Chief didn't want me carrying on duty (the reason I bought the M29 - can't have a big bullet .45??? then I'll carry a big bullet .44) and I didn't worry about the finish on it.

Check on the LE duty equipment makers.  It may be that no one sells the really nice holster anymore because most LEOs carry ugly (compared to the old days of Colt and S&W revolvers) semi autos supplied by the departments and no one worries about what the gun looks like after a few months of every day carry.  It ain't theirs and it'll get traded in after a few years anyway.

I think every holster will eventually wear the finish of the gun a bit. The more often you holster/unholster the more likely you are to notice wear. Carry guns are tools, they will get scuffed up and dirty. However, if you are just sporting a BBQ gun/holster combo, just holster the gun and leave it that way, you'll never wear a damn thing

My Glock 26 which I've carried almost daily for over 2 years shows only very slight wear at the muzzle. My G42 which I've been carrying on and off with the 26 for nearly a year now shows no signs of wear.

I wore my Glock in a Crye GunClip for a week or so and the left side of the muzzle now sports a custom polished brassy spot from the screw on my EDC knife rubbing it.

In my experience you have that backwards.  Kydex will give you some minor wear on the corners of the gun quickly, but then it pretty much stops.  Leather will wear the entire finish off over time.

Idiot scratches= Ugly
Finish wear from holsters= Beautiful

Yes, all holsters cause wear. It's the nature of the beast.

A nicely worn carry gun is a thing of beauty. I love the look of some good holster wear.

Put it back in your purse if this concerns you