I think a lot of the phemonema is a result of media and marketing. As a vector to start at, a lot of people are unhappy with their lives for various reasons. Most work a job as a means to an end, and spirituality/mental development isn't a big part of Western culture. We're seeing things like meditation and yoga entering onto collective awareness, but not exactly in any meaningful and integrated way as a norm of society. There's a hunger for fulfillment outside of the vacuum of materialism.
There is a large market for disenfranchised people, and this is where people like Tai Lopez, Steve Pavlina, Joel Olsteen, Jordan Peterson, Deepak Chopra, etc.—guides who've "made it"—come in. And with social media there are now a ton of "influencers" in the spotlight pushing their products or products for others. There are people I run accross on Twitter that you really need to be looking in a niche community to find, and they'll have around 30K followers and programs to sell. Same thing happens on YouTube, Instagram, Facebook. There's a market for life improvement, and the more economically viable it is, the more it gets advertised and put in front of more new eyes.
The people who get on board with this stuff and post it on their feeds are probably dopamine junkying it out, looking for validation...and incidentally getting others wanting the same in on it.