It’s a simple sales techniques that got co-opted from successful psychotherapeutic techniques (hence, insidious).

Create the frame that people believe (“there is something wrong with me”), then offer the solution, but pretend that they themselves are coming up with the solution (“self-help”), when all it’s doing is moving the dependency on help from trained, qualified therapists to someone writing a book, holding a workshop/seminar, etc. Often with very little in the way of training, qualifications, or experience.

These same techniques have creeped into healthcare, and predominantly moreso in the natural medicine world, where people are mostly getting their information from untrained, unqualified, inexperienced nobody’s who’ve read lots of blogs and saw a documentary, but are very good at getting attention on social media.

And then people wonder why they are still so sick, anxious, etc.