@fredrik222. The difficulty here is that a lot of people's experience contradicts the basic "facts".
As has happened throughout the history of science, in these situations advances happen when the apparent contradiction between "facts" and experience is probed and understood.
And yes there is the danger of snake oil, confirmation bias, and placebo effects, but effort needs to be made to rule those out rather than simply dismissing the empirical evidence out of hand.
BTW - that is a general rather than ad hominem comment.