It was not better. Power supplies in the 80s were not very high efficiency. They did not have much in the way of low dropout regulators meaning the boards blew waste heat constantly with few sleep modes invented yet. It wasn't even cpu cycles generating that heat, just resistive waste. All of the peripherals like disks and of course the CRT had quiescent draw as well.

So the 80s were not good. The 60s and 70s -- even worse. Gas had lead. And it spewed everywhere and we'll never get it out.