Because generally speaking, unless something is concretely documented as dangerous we don't just assume it is dangerous "because". Especially when that "because" is because of a well-documented, decades-long propaganda campaign by the federal government.
As far as danger, I think that, as with many things, it's about maturity, education and harm reduction.
I had a single bad experience with mushrooms, and it put me off ever taking them again. I was too young and immature (something like 15/16), and took about 5x more than I'd ever taken before. I can see now that it was obviously very stupid. If I'd been in a different location at the time, god only knows what could have happened to me - I'd say that, if abused, mushrooms can be far, far more dangerous than driving a car.
But - if the science backs it up, psylocilin could do amazing things for those with depression. And furthermore, sensible people can have amazing experiences. So as long as education and harm reduction is in place, I'm all for it.
Did you have a point to make?
People who are not well are known to 'self medicate'.
For example: Increase of alcohol use among people with preexisting problems is well documented. Link between tobacco use and schizophrenia is also well documented. See: "Smoking and schizophrenia" https://pubmed.ncbi.nlm.nih.gov/19794359/ "It has been suggested that smoking may be an attempt by schizophrenic patients to alleviate cognitive deficits and to reduce extrapyramidal side-effects induced by antipsychotic medication."
Psychedelics are not the type of drug people keep using if it harms them. If they don't work for you, you really don't want to do them again.
(ps. I would not recommend _regular_ drug use of any kind)
Be pro-shrooms but don't act like they're safe in every case. Education is required before partaking in anything, let alone shrooms.