It's never going to be a major moneymaker - you rarely encounter people who want to continue abusing it. 1 dose is sufficient for 6 or more months of mitigated symptoms, sometimes even allowing people to entirely escape negative thought patterns and depression. Psilocybin induces new synaptic pathways, helps balance out or suppress obsessive loops, so in combination with positive reinforcement in lifestyle patterns, habits, and changing environments, a single high dose psilocybin experience can radically alter someone's mental health and outlook for the better.

The literature is fascinating - one of the safest drugs known to science, yet one of the least exploited for medical or scientific purposes. There's a whole vast wealth of good data that will come from research like this, it's exciting.