It takes resources - a lot of them, including energy - to build the miners. It's a net loss if you can't run the miners at a sufficient duty cycle. Cheap mining power is about 4c per kwh. A $350 GPU at 200W (hand-waving) takes about 20c/day to operate. At $70/year of power, and maybe a useful life of 3 years, it's actually capital-dominated.
True- so if you lived in a zone with negative price, then you would throttle your GPUs otherwise and only go full throttle when you literal get paid to use the power. But duty cycle just for that would be low... I would need to look more at the stats. But if full time operation on average over the year was closer to (or less than) $0 for power usage, could you net a profit over the life cycle? I would surely hope so!
