The answer hasn't been found, as there is still a gigantic unsolved societal disease in the USA regarding alcohol. Tobacco too.

Whatever you think is working (stopping sales at 2am or whatever) isn't. It's farce. Humans can't handle drugs, generally speaking, and permitting some whole ruining lives over others is the peak of ineffective ridiculousness.

The fact that humans can't generally handle drugs (alcohol included) is not a reason to waste time and money and imprison millions of people in a misguided attempt to address the problem. (Not that that was what the war on drugs was even for, mind you.)