That's true, but optimization is always an exercise in economy. If the money is there someone will do the optimization, for instance, in the Bitcoin mining arms race you could see the writing on the wall for CPUs long before the jump to GPU's, FPGA's and eventually ASIC's.

In mobile phones I always expected battery life to cause a resurgence of things like assembly programming but it never happened, people are happy to recharge their phones. I wonder what would happen if someone introduced a smartphone OS based on old school principles jacking up the battery life to 5 days or so.