They don't need a breakneck GPU - they need a device like this that gives them new, intuitive input options.
That said, for any kind of 3D development this hardware isn't up to snuff. Anyway, the device seems more targeted at 2D graphic designers.
But trying to draw on an 1200 dpi A3 canvas (unsurprisingly) doesn't really work very well. But if I were to use it professionally, some of the things I'd want to do was draw high resolution A2 to A0 prints.
I've yet to play much with photoshop, so I'm not sure how well it handles a modest 20 megapixel image.
For me using Clip Studio Paint seems best so far, as it has dedicated tablet mode UI and is responsive enough, thought 1200 dpi A3 will might be too much for it at times.
It's misplaced priorities due to lack of knowledge, not that they don't benefit from high-end hardware.
So, yes, you can get two, even three iMacs for the price of a Surface Studio, but the specs will be nowhere near the same between the two.
I've said this in this tread before - you don't dump 4k$ on a desktop for mobile performance - when you spend that kind of cash you probably really need a high end workstation - think of the mac pro use case - and this device doesn't cut it as that.