I think OP is suggesting that a targeted ban on proof of work crypto will be more politically feasible -- particularly in the US -- than a carbon tax. Even the state of Washington (which is far more left/democratic/liberal than the US as a whole) failed to pass two different modest carbon taxes in recent years.

So while carbon pricing would be a more ideal solution, OP is suggesting that a targeted ban on POW crypto is a good-enough bandaid that might actually pass.