97% of all bitcoin miners will never mine a block in their entire useful lives. They will be manufactured, plugged in, they'll sit there, desperately guessing, never guess right, and be thrown out.
But it is right now.
We don't live in a world with carbon neutral power generation. We're not there. PoW is even encouraging people to bring fossil-fuel based generation back online just for mining and making the transition to low-carbon economies slower.
> I'm yet to hear a convincing argument against proof of work under the assumption of carbon neutral electricity generation.
Yeah, let's have that argument when we're closer to actually having that. Oh, and before you say "Increased demand will get us there sooner"... no, it won't, we already have a huge amount of demand that can't be met, it's making things worse.
POW is that, but worse.
Yes, and increasing energy demand for crypto is slowing down that move towards carbon neutrality. If you have more demand, you need more carbon neutral energy generation until you can be fully neutral.
In short, can they compete with traditional heating? Radiators, in floor heating, heat pumps, etc. I doubt it.