The margins on VRAM are pretty bad for them since they don't manufacture it themselves. And every memory module they add needs additional power delivery and mem

The margins on VRAM are pretty bad for them since they don't manufacture it themselves. And every memory module they add needs additional power delivery and memory controller muscle to drive, so adding that memory is going to raise the cost of the card significantly. Most games and consumer workloads won't use all that extra memory. Keep in mind video cards don't use the same kind of RAM as consumer CPUs do, they typically use GDDR or HBM.