Most things aren't necessary. Many things are net detrimental to society. We still allow the vast majority of them, because people are free to do what they want

Most things aren't necessary. Many things are net detrimental to society. We still allow the vast majority of them, because people are free to do what they want with their lives in this world. Just because you have kids doesn't mean that your wishes have more weight than theirs. The biggest harms from drugs come not from the drugs themselves, but from the fact that their users and sellers have been locked out of our legal dispute resolution system. Drugs only lead to violence as long as someone is trying to stop them. If they were regulated and sold openly, with just 10% of the funding that currently goes to law enforcement to futilely try to stop them instead being diverted to addiction treatment and honest non-fear-mongering education, they would result in an order of magnitude less harm.