I've always found, "We've the lost drug war" a silly argument. Why is the fact that drugs are still used a reason for no longer trying to eliminate them? Since the founding of this nation, the government has lost the war on murder, and rape, and theft. We're not throwing in the towel on fighting those crimes. We need a more compelling reason to stop fighting the drug war.
The crimes you listed are crimes against other people. Murder, rape and theft are part of what society has always said are crimes that cannot be tolerated in a civilization and it is universally agreed that those crimes won't be allowed.
Those who favor legalizing drugs and putting a stop to the growth of government that results from a War on its own citizens would argue that drug use is not a crime against other people.
Those who support keeping drugs legal will give you chapter and verse about people they've known or been related to who ruined their lives using drugs, and they will tell you that for the loved ones of those drug addicts, it was a crime against other people.
But the hurt you experience from seeing someone you love make bad decisions and ruin their own life is not the same as a property crime or a personal crime, and the comparrison is not justified.
The simple argument is that we are spending billions of dollars on it every year and getting no results for the investment. The money would be better spent in a fashion that actually does generate a measurable improvement for society.
It is similar to the argument against the bloated education budgets in the US. Public education used to be cheap in the US, good results with relatively little expenditure. The teacher's unions promised even better results if only we spent more money. Fast forward many decades and we spend vastly more per student with the same or worse results despite spending more per student than the rest of the industrialized world on education. That investment in public education was a waste -- vastly more expensive, no measurable improvement.
The problem is the government never has to justify its expenses in terms of return on investment. If we spend money, we should expect to get something for it. If we increase spending, we should expect to get more of what we were already getting. Any program that does not meet these expectations should be dismantled immediately, the money reallocated to other programs at worst or returned to the taxpayer at best. The War on Drugs is unambiguously one of these programs -- lots of money creatively spent and no real positive results.
In typical government fashion, they completely ignore the systems theory that governs this type of regulation and try to brute force their way through problems that can really only be solved by shifting the equilibrium of the system such that it settles into a more satisfactory state under its own weight, but that takes more brains than a typical bureaucrat can frequently muster.