1. In the 70s a lot of people in the West were taking psychedelic drugs, however, no major public health and/or civilization-level changes happened.
2. More compassion (operational definition = empathy + desire to reduce another person's suffering) does not necessarily equal more prosocial behavior.
2.1. Most modern tribes have been taking psychedelics regularly for generations. First, they are still living in tribes (see point 3). Second, with their increased moral concern they, nevertheless, go to war, kill, rape, pillage, torture, and enslave.
2.2. SJWs and radical vegans score really high on compassion and are willing to engage in violent behavior to defend their ideological beliefs. Most people already have a decent physiological capacity for compassion. Battling ideological possession may be more important.
2.3. You need people who score low in empathy and compassion for certain professions like trauma surgery, burns units, firefighters, judges, warfare and so on. Being high in empathy and compassion AND working in such fields leads to burnout, compassion fatigue, depression, PTSD and so on => 1. you increase suffering in the population + 2. you decrease the effectiveness of these professions.
More compassion does not equal less antisocial behavior and less suffering.
3. Creativity and openness are not always good. Creativity evolved in certain contexts and comes at the expense of other cognitive functions and with risks of certain mental conditions. "Messy creative ADHD neurotic" people are fun to be around and have genius ideas but you need greater numbers of "close-minded boring doers" to develop, execute and regulate those. Shifting the balance between creatives and non-creatives in a population may have unexpected consequences.
4. Having an effective intervention to treat not just severe but also mild and moderate depression may shift attention and resources away from battling the cause. We should aim at implementing measures that will lead to lesser likelihood of depression to develop in the first place (not counting the rare genetic cases). Such measures may be trace lithium in the water supply, population-level screening for immune reactions to food antigens, improving in-door lights, fighting light polution, having different work schedules for different chronotypes, a custom school curriculum and career development based on your BIG5 strenghts, "dorms for adults" to reduce loneliness, and so on.
Conclusion: psychedelics = promising, amazing area of research, great potential to improve certain things BUT:
1. maybe they will work, maybe.
2. we already have proven strategies how to solve the problems psychedelics may solve but we need ways to implement them on scale.
promising = yes
priority = no