Apple has official repair locations all over the planet and they stock parts long after products are discontinued. Yes it kinda sucks that they killed third party repair but having an official location with official parts is actually more useful than being able to do it yourself but not being able to get parts.

For my pixel 2, while there were no technical restrictions preventing me from replacing the broken camera, the screen was glued in in a way making it very difficult to open without smashing. There were also no places to buy the camera other than what seemed to be cameras stripped out of broken/stolen pixel 2s.