No one is admitting defeat, they are just telling you to stop focusing on the symptoms and start focusing in the problem. You want to address drug misuse problems in western society? Start by addressing the problems that actually highly correlated with it. Help for unhoused persons. Better mental health systems. Those two things alone could curb a huge majority of drug misuse. If you take care of the symptoms then the problem will be mostly solved without need for any criminalization, be it criminalizing supply or demand. For the rest of people I think more funding of rehabilitation and drug education (and no, just telling people to abstain from drugs is not good education, just like abstinence is not good sex education).