And that's the problem right there...
The risk is not always self contained...
For the most part it is. And when it isn’t we’ve got perfectly reasonable laws and regulations to model after. We have drunk driving laws, and actually all of them were long ago tweaked to cover any form of “perception alteration” like illegal and even prescription drugs (yeah those “do not operate vehicle” labels are actually legally enforceable because that’s you being told your driving will be impaired). If one goes violent on drugs we have laws about that. If one stops taking care of their kids we have laws about that. We don’t need the WOD, which you’ve acknowledged has failed, to enforce these other laws when they are violated by people on drugs.
And as for the general familial wreckage of addiction, that happens no matter what the person is addicted to. Watch a couple of episodes of Hoarders on A&E, their families are just as traumatized as any dope fiend’s families and nobody is trying to outlaw purchasing.