Perhaps you know already, but for the record the Oregon law only allows psilocybin use under trained supervision.
In the case of alcohol, in my opinion we need a similar cultural attitude. Your state flips on your 21st birthday from absolute prohibition to...as much as you want. We need not so much a place for people to safely binge, as to guide them to considering for themselves why they would want to in the first place. Some people always will of course, just like there will always be people who drive like assholes.
That reduction is lossy. There's a large middle ground where free individuals make agreements with each other to cooperate in ways that make them all better off.
The previous commenter's handle alludes to one possible item, crystal meth: that's a substance that doesn't seem to have any redeeming value, and a lot of risk for other cooperative endeavors. So perhaps we should all agree not to traffic in it. (And if we later find a good use for it that stance can be revised.) Mushrooms have a very different calculus, and all that said I agree in general that the drug war has been very badly conceived and executed.