I'm in the business and this post is 100% accurate.
Techs are now mostly computer technicians.
Warranty labor costs are so high for the manufacturers that they now require the vehicle to be plugged into a dedicated online system that steps the tech through each step of diagnosing a problem. These procedures are designed to fix the vehicle as cheaply as possible and, even if the tech finds the problem, he can't proceed without the factory's say so.
Here's how crazy its gotten..
If an engine has to be torn down, GM is one I know of, they will reuse the coolant , and the engine oil and filter if they have not been scheduled to be changed!
If you want fresh coolant, oil and filter, you have to pay for it, even though the engine parts were replaced under warranty!