What is the success rate of folks who use heroin with some effort to not be addicted ... and what is the cost of getting them out of the cycle of addition? and what is even the success rate of getting them out of that cycle?

The impact of failure to somehow prevent yourself from being addicted can be catastrophic ... even if you are successful in getting them out of the cycle of addition. And that impact can extend WAY beyond the individual.

I'm open to the possibility that some drugs really can't be used responsibly by enough people that they absolutely should not be legal.