Nvidia wants you to buy their datacenter or professional cards for AI. Those often come with better perf/W targets, more VRAM, and better form factors allowing for a higher compute density.

For consumers, they do not care.

PCIe Gen 4 dictates a tighter tolerance on signalling to achieve a faster bus speed, and it took quite a good amount of time for good quality Gen 4 risers to come to market. I have zero doubt in my mind that Gen 5 steps that up even further making the product design just that much harder.