It seems to me you've not thought through the game theory of banning cryptocurrency very much.
There's an immediate competitive advantage (in the form of increased business activity & tax revenue) to the first country to adopt clear, consistent rules regards CCs and their use. If a few big countries try to ban it, that competitive advantage becomes even stronger for any country willing to buck the trend.
There's an immediate competitive advantage (in the form of increased business activity & tax revenue) to the first country to adopt clear, consistent rules regards CCs and their use. If a few big countries try to ban it, that competitive advantage becomes even stronger for any country willing to buck the trend.