I think one of the most frustrating things with shop work nowadays is that manufacturers spec to techs that whole systems need to be replaced, even if it's only one small thing. In many cases, manufacturers have forced shops to charge outrageous prices.
Gone are the days of replacing simple brake pads in a shop. If you take a car in to a shop for brake pads, they'll replace wheel cylinders, rotors, master cylinder, and expensive sensors unnecessarily. It's such a waste, and most people don't know anything about mechanics. Dealerships are the worst with this, and I don't see why people trust dealer service shops, except for special cases.