The grift of giving some free advice that may or may not work, to get them hooked so you can sell bad advice that when it doesn't work they say it didn't because they didn't believe enough or try enough and there is yet another book for them to buy which then locks these people into a spiral of buying only their advice....

Is such a long running and stupid grift for people to still be falling for this strongly.

We are right back around to people selling blank books for you the reader to fill out with the great plan that's gonna work. But people feel directionless and scared of the future so idiots will seek comfort anywhere they can.