disc brake dust shields

The brake dust shields should be galvanized steel, which is one of the best ways to prevent corrosion on metal. They're probably eletrogalvanized rather than hot dipped, so the zinc coating likely isn't super thick. But the reason they don't look detailed is because of the combination of brake dust and heat, which is literally breaking down the metal. Paint won't do better than that, and powder coating isn't going to stay perfect either.

If you want your suspension to remain detailed, you can either spend a lot of time cleaning it, or not drive your car.