It's a common mistake, and the above fact is going to be extremely difficult for many people to believe because of the comfort-zone of entrenched beliefs and confirmation bias, but RV is actually not a grift and is a real thing.

If you're still having trouble believing this, but consider yourself an open-minded person I encourage you to try RV for yourself. I believe there is a subreddit that is not terrible. For RV, I don't think you need to believe it works, nor have a theory how it could, in order to get results, however keeping open-minded is useful to getting and interpreting the data you receive in RV.