No it hasn't, the war on drugs has actually been pretty successful. The problem is that people don't understand what success actually looks like.
How is the war on murder going? Is it a failure because we still have murders? Should we legalize murder because we can't stop all murders?
I would say the war on murder is going pretty well. We would have far more murders if we made it legal than we do now. That we still have some murders does not make it a failure, the fact that it is kept to a relatively low level of murders, actually makes it fairly successful.
Exact same thing with the War on Drugs. Do you want to see what not having a war on drugs looks like? It looks like this:
By 1900 50% of the adult male population of Manchuria was addicted to opium. China thereafter went through one upheaval after another with Japan eventually invading and taking control of the much larger nation.
That's what not having, or in the case of China, losing a war on drugs looks like.