You keep ignoring the prescription pain pill argument because it's inconvenient for your talking points.
Prescription pain pills are easy to get, legal with a prescription, and not nearly as stigmatized in society as hard drugs.
As a result, we now have a rapidly growing epidemic of their abuse.
This epidemic is due to both the legality and accessibility.
You are insane to think that hard drug usage will not sharply increase if we make them all freely available to anyone having a stressful time in life, or anyone who wants to try experiencing them.
Jeff Bezos of Amazon once stated that, with each extra click required to buy something online, sales decrease sharply.
The same thing goes for drug abuse. There is a barrier of entry to acquire hard drugs. You need to have a connection to a dealer from whom you can acquire it. You need the willingness to make contact and deal with such a shady individual. It's also illegal, and you might fear getting in some trouble for buying it. These are not insurmountable barriers, but they are barriers nonetheless.
For example, if I decided tonight that I wanted to smoke crack, I couldn't do it. I don't know anyone around here who could hook me up with a crack dealer. Once I return to Vegas, I could probably acquire it, but only because of my connection to poker, which most people don't have. Otherwise it would be difficult for me to acquire.
The person dedicated to acquiring hard drugs will find a way to do so, but this barrier shuts out the less dedicated person who might start using if it were easy, but otherwise doesn't want the hassle.
You cannot compare this barrier to what you suggest -- making it freely legal and available, and just trusting that we aren't going to get a whole lot of new addicts who suddenly find it easy and legal to acquire.
Furthermore, as I stated earlier, those involved in the current drug trade are not simply going to shrug their shoulders and return to normal society.
Much like broke poker players have a hard time returning to regular employment (especially at a low wage), so would displaced drug dealers.
Again, I am not sure what you are trying to accomplish. Do you think that most currently imprisoned for drug dealing would be leading productive lives within society, if only we could strike down drug laws and legalize everything? Because I find that highly doubtful. You seem to want a bunch of criminals released who at best will resort to illegal activity to score easy money, and at worst will get deeply involved in illegal, violent enterprises to do so.
Unfortunately I think too many people see our eye-popping prison numbers, and either think "conspiracy" (omg private prisons, trials must be rigged) or think "instead of changing the people, let's just change the laws so what they're doing isn't illegal anymore".
Not the right approach.