This is a bad comparison. DRAM margins are razor thin and unlike transistors, DRAM has not gotten much smaller, which is the main cost savings gained from process improvements.
Instead, server and accelerator vendors want ever faster and higher performance DRAM, and so these performance gains trickle down to consumers, but nothing is driving price down.
People on here literally think Moore's is a natural law and if computer hardware isn't getting 15% cheaper every year there must be funny business involved...