For the first one the War on Drugs or frankly the War on X proves that governments are incompetent at actually enforcing contraband. Factor in the fact that people will be driven by the primal instinct to protect the future of their children versus momentary pleasure of drugs or prostitution and I think that makes it even more futile.
For the second one I’m not an expert but I imagine that there is a solution by making even stronger encryption that makes quantum attacks too expensive