Ah, but that’s by design: it also acts as a soothing white noise machine.

Then you might point out the exhaust and all it’s associated wastes, but that’s by design: it produces a heady and aromatic product for recreational huffing.

Then you might point out the vibrations, but that’s by design: the engine also provides invigorating massages to relax taut muscles.

Let's allow a rounding error for 99.51% shall we?

A 1000W computer will make exactly as much heat as a 1000W heater.

All space heaters should be coin miners (or some other borderline useless energy wasting tech, like AI training). Change my mind.

But even a furnace/fireplace is subject to incomplete combustion, where some portion of the wood is transformed into byproducts that rob some of the energy of the fire. There's actually a big difference in the amount of energy you can get out of a fire, depending on the type of stove that's used.
That's some of what NGOs have tried to do for developing countries - find cheap and easily produceabke stove designs that can reduce the amount of wood needed and improve air quality in the home.

In this economy?

He doesn't burn very well.

so a heater and a humidifier all in one, now just have to make sure that it doesnt eat all the oxygen or make it rain inside