Far, far more people are gaming on Nintendos, Playstations and Xboxes with iGPUs and relatively weak total processing power than on 400W GPUs. You're making the mistake of thinking only the fastest can win but in real life the good enough almost always wins. Streaming will do even more for the death of the dGPU than performance alone can compensate. You already rely on someone else to rent your game software from, doing the same for the hardware is one small step.
Mathematically GPUs can keep getting better at churning out more pixels faster but the biggest limitation is really entirely subjective. Past a certain point the returns are diminishing in terms of what your human eyes and brain can experience as an improvement.
Laptops will never be as fast as workstations but they're fast enough to outsell any desktop. Any reason to believe GPUs are intrinsically immune to this "fast enough"?
Mathematically GPUs can keep getting better at churning out more pixels faster but the biggest limitation is really entirely subjective. Past a certain point the returns are diminishing in terms of what your human eyes and brain can experience as an improvement.
Laptops will never be as fast as workstations but they're fast enough to outsell any desktop. Any reason to believe GPUs are intrinsically immune to this "fast enough"?