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.