To steel-man OP's argument, > Regulations and limited availability don’t cause more people to use drugs. All else held equal, all this does is increase the pr

To steel-man OP's argument, > Regulations and limited availability don’t cause more people to use drugs. All else held equal, all this does is increase the price of doing drugs. There are arguments to be made about the history of the demand for drugs. I think we can safely say, though, that it stays at a stable 'Some people really want to do them'. Whether or not that means growing a plant or potentially getting shot depends on the regulations.