Because these things are rare as gold in the first place as being Linux ready isn't a focus for most OEMs, sometimes severely lag behind the competition in feature support (e.g. limited to UVC webcams with crap quality), have serious availability issues (Framework), you have a tough time getting service or spare parts, or barely any resale value, or limited choices in screens (which is the one and only thing keeping me from a Framework - who the fuck wants a 3:2 screen?). Also, tough luck getting firmware updates for embedded components.
Apple devices, spare parts and repair centers, in contrast, are widely available across the world (okay, maybe not in places sanctioned by the US), firmware updates come around when needed and hold their resale value for years.