I'm no crypto enthusiast, but that's not the same argument. You are not moving demand to physical proximity of the renewables in that case, whereas miners claim they can.
The correct answer is to connect the energy source to the grid or to do something useful with it at the point of generation. If it's being consumed instead to guess random numbers the economic incentive to do something useful with it is suppressed.
Miners don't really want to use energy only when it's at a surplus though. Because the equipment is expensive and due to the difficulty increasing it's only viable a short time. So this is an argument that also doesn't really fly (and draws attention to another issue; the e-waste)
Sure, but the gotcha there is that we shouldn't be using resistive load heaters, they're only 100% efficient. Heat pumps are several hundred percent efficient - 300-600% in fact. Whereas resistive heaters convert electricity into heat directly, heat pumps use energy to move heat against a temperature gradient.
The idea that you can be paid to waste this power just creates economic incentives against the improvements we actually need to be making.