A deliberately stretched example. Apple laptops are claimed to not need camera privacy shutter, because the recording light is hardware controlled, so the user always knows when the camera is recording. What if what if recording ight on non-genuine camera is software controlled via additional register and simply automatically turned on on recording to not cause suspicion, but could be manually turned off via software?
More generally the issue is about broad compatibility. People often mention screens and batteries as being observably worse. Sure off-brand screens do display pixels and batteries provide power, but they do that at an observably lower quality. A networking module may not support some "smart" features and so on.
Hardware quality levels are what differentiate macs from PCs. Whatever you say about Apple, you have to agree that with Apple you consistent (and relatively high) quality levels. With PCs it is quite another story. You can buy "business class" laptop that has durable frame, quality components that easily interface with the rest of the system and things mostly "just work". And then there are shit tier laptops where BSODs show up if you look at them weird, you need to hunt down right versions of drivers after every OS update and some features outright do not work.
Apple could maintain the quality floor mostly by being in tight control of hardware. With independent shops installing shit-tier components Apple is going to have shit-tier macs in the wild. I can understand Apple. But on the hand, I do not want to be forced into genuine-only programs, as long as I can make an informed decision that I am sacrificing something. it's not a small thing. An older laptop is quite often not worth to fix with genuine parts (that are expensive in part due to quality control), but it may make sense to revive with with an off brand component.
I have no idea how to coalesce these two ends of a stick.