Except that no real mining hardware uses only 20-30W.
I'm only running one Compac F its about 17Watts at the socket and its being run by a Raspberry PI Zero 2W, which is about 3 watts at the socket so in total approx 20Watts. As a lottery miner thats great, it blends into the background a costs litterally nothing to run, especially given the house is running mostly on solar & battery.
But, yes a real miner you're looking at more than 3000Watts at the socket!