Apple doesn't actually repair anything. Apple outsources this to shops with wildly varying qualifications. Often incurring unnecessary cost. And no, they wouldn't repair them for free.
Anything that breaks within the warranty period Apple fixes for free, and often even outside the warranty period. I, like many others, have had an Apple genius waive a repair charge out of warranty if the device should not have failed.
And whether your claim of their outsourcing is true or not, Apple is still on the hook for warranty on the repairs. I highly doubt it’s common.
Lastly Apple has by far the highest customer satisfaction in the industry in a good part because of how they handle repairs.
I think you might want to look into that. A good place to start is Louis Rossman's Youtube channel (he fixes Macbooks for a living and a recurring feature on his channel is how Apple and other companies do "repairs"). https://www.youtube.com/user/rossmanngroup
How many Macbooks, iPads and iPhones have you sent off for repair?