You’re not wrong, and I’m not saying other actual side jobs waste more energy necessarily, but the gap may not be as large as you think.
(hours spent on research, hardware acquisition, setup, and maintenance) / (net profit, after accounting for hardware depreciation and obsolescence)
The only way OP's method is worse is the capital costs of the processors. The energy spent on the actual heating is converted with 100% efficient either way.
Here's a neat video about them: https://www.youtube.com/watch?v=7J52mDjZzto
My house is from the 1800s and only has heating for the kitchen/dining room/living room.
As far as it being “Monopoly money”, >40% of US dollars were created since the start of the pandemic. Yes, there’s a lot of technical details there and most of that money isn’t “in circulation” and many would argue that the way this is being done shouldn’t be inflationary, but it’s never been done at this scale and we do have the worst inflation in 40 years so it may be a contributing factor. Contrast this with Bitcoin which has a fixed known supply, or other crypto currencies or tokens which may exist primarily for their utility, and IMO “Monopoly money” isn’t a fair characterization. Even BTC which has little in terms of “utility” can be used to move money equivalent to billions of dollars a far lower cost than the traditional financial system so it has its advantages.
At least blockchain related technologies enable new use cases, IMO it would be more fair to blame something like Electron and inefficient web technology replacements for native apps for being inefficient and wasting energy. But I wouldn’t do that either, it’s silly. The people making software don’t control energy policy and that’s the real issue.