I had to get warranty service for my first gen iPad a few months after release because the speaker stopped working properly. Oh, and I’ve had the AirPods Max condensation issue kill off a few pairs of AirPods Max during the warranty period (and once outside of the warranty period, necessitating a new purchase). That said, I think I’ve finally solved that issue by only using the AirPods Max indoors and using a pair of 2nd gen AirPods Pro outdoors instead. Of course, I cringe whenever I see people using the Maxes outdoors or on the subway, especially during summer, because it’s only a matter of time until the condensation issue hits them.
Other than that, though, I’ve had to had a few extended warranty product repairs, mostly bulging batteries but also case repairs back in the day of the white polycarbonate MacBooks. Those things looked great, but, boy did the plastic discolor and chip!
Edit: I’ve never returned anything, though (Apple or otherwise). I’ve never really experienced buyer’s remorse over anything, with the possible exception of a few pieces of furniture that ended up being less comfortable and useful than they looked or a couple of items related to hobbies I was exploring that I ended up not sticking with. Maybe it’s because I tend to do research when buying anything big ticket and wait until I can pay out of pocket? (Which means that I’ve already darn well made up my mind to buy the item before I press the buy button online.)