I'd say that the CPU example actually proves the point. A computer today costs roughly the same as a computer in the 1980s, and it also consumes roughly the sa

I'd say that the CPU example actually proves the point. A computer today costs roughly the same as a computer in the 1980s, and it also consumes roughly the same amount of energy as a computer from that era. We got faster computers because we got better at making transistors. If we look at laptops, a device which consumes 200W already gets hot enough that it is uncomfortable to actually place on your lap. A 1kW desktop computer is pretty much impossible to cool. At our current population, those 5 million exajoules a year is a constant power consumption of roughly 16 megawatt per person. For comparison, that's about the same magnitude of energy you'd need for every human to launch a Falcon 9 to eat lunch in the ISS. Once figures get this big, you simply run out of things to do.