Crypto mining is unique in that the absolute consumption provides no benefit at all. The "work" consists purely in demonstrably having spent a certain amount of

Crypto mining is unique in that the absolute consumption provides no benefit at all. The "work" consists purely in demonstrably having spent a certain amount of value, and the energy is purely an unit of accounting. So if you could manage to make this unit more expensive for EVERY miner, the accounting system would work as before, the safety properties of the system would be unchanged, and less energy would be used. I can think of no other use of energy where this situation holds.