Science generally works on IF Then statements when it comes to treatment, IF you take this drug your blood pressure will increase, IF you exercise more your life expectancy will increase, with mental health issues there very few IF then treatments, there are only if maybe treatments, this is for a slew of reasons such as how we don't really understand it, symptoms can be caused by many different underlying issues, and legal risk of prescribing something that isn't proven effective. That being said, the IF maybe treatments are the only way to treat mental health, Psilocybin falls in this category.