In the past, I've tried a lot of recreational drugs, including some opioids, and without trying to, I can't see how I could get myself addicted to opioids or benzodiazepines, but I know a LOT of people would.

As far as I remember, only 10% of people who ever used heroin get addicted to it. But that still leaves 10% at a very high risk, because of their neurochemistry and life circumstances.

So I don't think ALL drugs should be legal.