Most people get started on drugs because the drugs came to them, not the other way around.
I believe this is still a fact. In the past, most drug users and addicts were recruited by petty dealers, who were users and addicts themselves. The bigger distributors would front them a small quantity at wholesale prices. The petty dealers would sell enough to pay their debt, and smoke/snort/shoot up their profit.
People also got addicted to various prescription drugs. More recently, we had the opioid crisis.
My position is we should deal with the problem pretty much how we deal with alcoholism.