Psychedelic drugs (LSD, psilocybin mushrooms, MDMA, etc.) are incredible for treating mental health disorders, why doesn't the government use them and instead chooses to overprescribe harmful pharmaceuticals?

The evidence is clear that these drugs are useful for treating a multitude of mental health and psychological problems, and most of them are not even addictive. Why does the government not use them at all, but instead prescribes everyone drugs that are addictive, cause tons of side effects, and are just overall dangerous.