First of all I clearly do not think all supplements are placebos but frequently responses to supplements are placebo responses. A fact about supplements is that when supplements are taken there are very frequently noticable effects. When ill, change is viewed as a positive and the perception, which can be an illusion, is that one is moving away from being ill hence a placebo response.
The difficulty with supplements as placebos is that frequently change is not for the better or even biologically neutral and can even be for the worse which I think is all too frequently the case with supplements. Supplements are a minefield.
Individuals are biologically programmed to try to improve their health. Most people have a strategy for staying healthy. A non fad diet strategy, excercise, and continous learning are right now by far the safest way to go.
That Silicon Valley is full of individuals who take lots of nootropics and lots of supplements does not bode well for Silicon Valley’s future. I think one day supplements can be a key part of a healthy way of living.