[Decade]

In short, Apple does things in non-standard ways without explaining how to get another OS to work.

Apple doesn’t prioritize lack of binary blobs. The EFI firmware is all proprietary. All their Wi-Fi have been switched to Broadcom.

They do weird non-standard things to the Thunderbolt controller, e.g., you have to lie to the firmware and claim to be macOS in order for it not to disable the Thunderbolt controller.

Newer MacBooks hide a bunch of hardware behind the proprietary T2, and whatever embedded OS runs the Touch Bar.

MacBooks are not ideologically pure, and sunk efforts to get an OS working on other machines are often wasted on MacBooks because Apple does things in bizarrely different ways.