Problem is Wacom manufactures the PCB and the PCB is actually rather thick because Wacom doesn't use hyper-modern extra thin stuff.
Its just a grid of wires, basically, theres no reason that it HAS to be that thick, just that they've essentially not changed how they've been made for the past decade.
Wacom doesn't think they need to compete in the tablet market vs modern touch digitizers, so they don't bother doing so, even though they'll license/sell it to anyone with enough cash.
Its confusing to me that Microsoft and Wacom couldn't make a deal: I've used Wacom tablets before, hardware wise, its the best pen interface I've ever used; software wise, well, the apps themselves were laggy as fuck, but Microsoft (due to Surface) has been making a huge push to fix that, and there is literally no reason for it to happen anyways, especially if scribbling with a mouse doesn't do the same (its not caused by the driver or the hardware, because Wacom sample apps don't do it).