I don't think supply is limiting the amount of drugs that abusers are doing.
https://news.ycombinator.com/item?id=17608261
It's been effective in the countries that have tried it since. Overdose is the failure of dose management. Harm reduction is less profitable than addiction. Wars create jobs and huge profits. Collateral damage is the human cost. Success wasn't the goal.
"Analysts pointed to two major reasons for the increase: A growing number of Americans are using opioids, and drugs are becoming more deadly. It is the second factor that most likely explains the bulk of the increased number of overdoses last year."
And they are becoming more deadly because the street drugs are being laced with fentanyl.
At the same time the news is constantly full of stories about a rise in opioid overdoses.