Magic mushrooms, LSD, and cannabis are in a different universe psychiatrically, addictively, and experientially. It's like comparing viagra to chemotherapy: yeah, a blood thinner carries extra risks for certain subpopulations, but chemotherapy has visibly destructive side effects on the entire population.
What makes you think the next demand won't be for other drugs as well?
[1] https://academic.oup.com/bjc/article-abstract/50/6/999/40402...
The short version is that, for those other drugs that the grandparent listed in their comment, they are already scheduled for medical usage. Only the psychedelics are scheduled away from any legal usage.
Well, there is a whole lot of other things that can also improve your life. Why go for riskier and less understood ones? I think they should be allowed in some cases but I'm very pessimistic about readiness of society to mass usage.
Mushrooms and other psychedelics have great potentials to improve mental health, if used wisely. There have been studies that show psychedelics successfully being used to treat depression, PTSD, and addiction. This kind of use is the opposite of abuse.
It is possible to abuse psychedelics, but it is rare, and one can minimize the risk by educating oneself thoroughly about them and by using them with a clear, constructive intention, in a quiet and safe setting, with an experienced person you like and trust, and with confidence in the identity of the substance and that you're taking the proper dose. I'd strongly recommend reading James Fadiman's Psychedelic Explorer's Guide[1] for more detailed suggestions.
Like the Prohibition of the 1920's, decades of the War on Drugs has utterly failed to make us safer. In fact, it makes us less safe because people have and will continue to use drugs, but because of the drug war they often are mistaken about the identity of the drugs they're using or the drug's dosage, leading to overdoses and other adverse effects. The War on Drugs also encourages and makes organized crime more profitable and leads to great violence, not to mention the effect of arrests, imprisonment, and killings by police on non-violent drug users and their families.
A tragedy and an outrage is the only way to describe the War on Drugs, and I have a very hard time understanding why anyone who's educated themselves on these issues would support it.
[1] - https://www.amazon.com/Psychedelic-Explorers-Guide-Therapeut...