No, it removes the extra harm created by our bad policies such as a lack of regulation leading to a fentanyl tainted supply of heroin
We can still age restrict like we do with alcohol, we could even implement a licensing system where, similar to driving, education requirements must be met in order to purchase a given substance. There are many different things we can do, and nearly all of them are better than our current system
Not to mention I'm only discussing the effect on direct users, our foreign policy concerning substance legality in other could tries has absolutely wreaked havoc. Not only through our treaties with European countries but especially south america
In the US anyone can already drink as much alcohol as they want, smoke as many cigarettes. Both of those have immensely harmful health implications, generally worse than other drugs such as cannabis, MDMA, LSD, or even heroin. Heroin won't give you cancer, neither will LSD and no, the short term effects of those drugs do not make them worse, that's a load of shit spread by incorrect government propaganda
There is evidence from multiple countries now that supplying people who have a current addiction with clean, high quality drugs and gives them a safe environment to use reduces deaths, new addictions, and harm overall. Yet here we are, throwing people with problems in jail like that's somehow sensible. Its not, not even close. The way the US treats people with issues is absolutely disgusting