If you get a magnifying glass out, Glocks have a matte finish, which resembles a stipple pattern.
Where that stipple is worn smooth, it gets shiny. But, the finish is still there, it's just buffed to non-matte. Which makes it stand out. Which attracts the eye and causes worry. Worry is generally a waste.
Well, went searching, I have no photos of my Colt .380 Government, which has well over a third of the finish gone to bare metal, yet it refuses to rust (a good thing in my book).
My Gen 1 G17 had all kinds of buffed-down edges, but, none were through the Tennifer, even though a couple looked that deep.