I told customers to look at plating like it was paint or stain on wood.
Paint, or nickel or decorative chrome plating is like paint on wood. It's on the surface. It can crack and peel, and moisture can infiltrate under it and lift it off. This is why decorative chrome and nickel can flake off or bubble up exposing rust under it.
Stain, or hard chrome partially penetrates the surface.
Since it's IN the wood or metal, there is no "underneath". For that reason hard chrome can't crack, chip, or peel. While the metal can rust due to porosity of hard chrome, it's far more durable then bright nickel or the chrome used as decorative coatings for cars and motorcycles.
As for gun finishes, hard chrome is still the best all around gun finish, which is why it's the favorite of most custom gunsmiths when looking for a durable finish.