For example, volume cost of a basic PCB is in the region of 1 cent per square cm, but a $40 PCB in volume can easily come from many layers and a weird stackup (not to mention that this may be up to about 100 sq cm).
They aren't created by traditional litho + etch, but rather by a process called modified semi-additive processing (mSAP). iPhone, apple watch, etc PCBs are basically the same as CPU/IC interposers on a large scale.
Definitely not 1 cent/sq cm cheap, but they have massive volume and high price points. It lets them get the insane part density needed these days.
Apples track record is refinement/perfecting for mass audiences not blue sky innovation. I’m looking forward to seeing their entry in this space should it actually launch.
The rumours were similar for the iPad. So much so they poked fun at those rumours when they shared the actual pricing which was shockingly low.