Whatever it's merits, part of the reason why fasting has tougher traction is that it's harder to sell/make money off of. Versus all the (regulated & unregulagted herbal) supplements out there.
For me it's crazy how much it makes the senses pop when doing a longer fast. As someone who lives a computer/indoor existence for longer stretches. The best finger/touch/taste/color awareness sense I can remember in a long time. Also helped get me over a couple of food aversions, and makes kale taste a lot better.
Some doctors like Jason Fung have been doing research on incorporating fasting & diet changes for diabetic/insulin resistant patients as well. All something to do your own research/trial-and-error on.