[greenn]

Third parties are perfectly capable of making replacement parts that match the OEM parts in functionality and quality. This has no effect on integration. The other parts of the phone don't care who manufactured the part, unless they were programmed to, as long as they are functionally equivalent. The user certainly doesn't care who manufactured the part as it does not effect the user experience.

[anonymouse008]

3rd parties are very much not able to match. Just do a side by side of screen quality and battery life. That is what upsets a customer more than anything - but they never know exactly why.

(Old 3rd party repair shop; thousands of data points)

[dkonofalski]

I think when you look at it from a profit-driven lens, though, third-parties are always going to have to compromise on something to keep costs down in order to make a profit. Apple, historically, overcompensates on its parts and has higher tolerances so, in order for a third-party to be able to make replacement parts at significant enough profits, they need to be parts that don't match the OEM in quality or function, by definition.

Just look at screen repairs. Apple checks in software to verify the integrity of some of the hardware in screens and, in the past, it led to people being locked out of their devices when they were repaired with screens that had dummy FaceID/TouchID sensors.