iGPUs have climbed high enough that they are overpowered for "normal" tasks like video watching and playing browser games. They can even do 1080p 60 FPS gaming to a decently high standard. And we've already proven via ARM that RISC architectures are more than ready for everything from embedded to high-power compute. What happens when iGPUs get good enough for 1440p 120 FPS high-end gaming? Game visuals have plateaued on the rasterization front. Once iGPUs are good enough, nobody will have much reason to get anything other than a tiny mini PC. The last frontier for GPUs will be raw supercomputing. Basically all PCs from there on out will just be mini machines.
The next few years will be very interesting.