This is a great thread. Thanks, @Ho-Chi-Minh, for starting it.
I think it will take a long time (especially here in the US) but I think that some kind of psychedelics - perhaps "next gen" ones that don't even exist yet - will be made available. Probably first for medical treatments and then OTC for recreation/self-exploration purposes. What MAPS is doing, for example, is the first step. It was a HUGE deal in the neuroscience community when the US gov't lifted the ban on using hallucinogens and empathogens in NIH-funded research. These compounds are so powerful and their effects so intriguing, we couldn't wait to get our hands on them! We can use them to study how the brain works and to develop new treatments for mental illness/CNS disorders. Once safety is established and regulation systems put in place, we'll see hallucinogens/empathogens on the market.
I can imagine a therapist discussing the trauma that led to severe PTSD and social anxiety, their memories, how they felt, the triggers that set off symptoms and then being told to explore that again under the influence of a hallucinogen, perhaps allowing the easier dissociation of the traumatic event (for example, a bomb) from its context (the market where it exploded) so that being in crowds no longer is a trigger. That kind of thing.
I'd like to see something like a licensing process to be able to use them recreationally. If people are educated about the risks, how to ensure public safety, and how to MAXIMIZE the experience for enlightenment, I do think humans would benefit tremendously.
tl;dr...