Part of my city and guilds mechanics course was of course about brakes, if all people did was just remove brake pads and replace them with new, you'd eventually end up with a build up of rust and corrosion on the caliper carrier that holds the brake pads in place and eventually the caliper sliders seizing, this then would not let the brake pad move freely in the carrier, resulting in a siezed or sticking brake that worse come to worse could boil the brake fluid and result in loss of the brake pedal, I've seen it many times. This is what I call brake servicing, where on every car I service the first job is to remove the wheels and strip the brakes, to see if anything needs replacing, if not the pads are all wire brushed down, uneven edges on the pad filed down, corrosion on the brake discs chipped and filed off, then the caliper carrier thoroughly cleaned to ensure the pads can move freely, a little copper grease applied to the top and bottom of the pads and grease and on the caliper sliders, then put back together. wire brushing the end of the hub to ensure the wheel doesn't become stuck on the hub and again a small amount of copper grease, and spray the brake pipe unions with waxoyl.
I can agree not all garages do this , like I said good mechanics and garages I know of do, it's called a proper service, none of this check and report bull. For those who call getting a oil and filter change a service, it's not, it's a lubricant change. Just the other day there was a thread stating a fellow member had a sticking brake, it's all due to lack of real proper servicing. Oh and just for good measure you'll clearly see I mention nothing about copper grease on any wheels. I was referring to not seeing any copper grease on the brake pads.