It shifts, rather than reduces, costs. No altcoin has used a PoW where memory latency dominates computation. Home users will never be able to mine profitably

It shifts, rather than reduces, costs. No altcoin has used a PoW where memory latency dominates computation. Home users will never be able to mine profitably (except by claiming their electricity is "free"), but the hope is they can do so within an order of magnitude loss of efficiency.