The real issue is that old hardware use a lot of electrical power. You can get a small Single Board Computer with at least as much computing power as those but using 20 to 30 time less electrical power, and fitting in the palm of your hand.

It's not really a real problem for most retro computing enthusiasts; it only comes out to a couple of bucks a month in electricity, and that's assuming you leave the computer running all month.

It's not an issue, it's just a price to pay.