That said, criminalising drugs has absolutely made the situations around and with them worse for more people. Those with the greatest gain in the current situation are the warlords in South America, the commercial jails and politicians stoking fear of drug use.
A great number of people can and have used a wide range of drugs successfully, peacefully, creatively, introspectively and with joy for 1000s of years. The current predominant legislation doesn't seem to reflect the will of a huge number of people. I don't have stats to say "a majority", but it wouldn't surprise me, especially if you include alcohol.
The problems exist. Better methods need to be sought to deal with them than criminalisation.