Nutrition is run on fads - see whole fitness and healthy food bullshit. Nutrition supplements ended up being a loophole that allows pharmacies and pharma companies to sell all kinds of random stuff that they can't or don't want to, show is safe, or doing anything at all.
I wonder what will come after the protein boom? My guess: Fiber is back because you need to "fibermaxx" when taking GLP-1 antagonists. I can remember some of the funny adverts in the 1980s of old people taking fiber supplements to "stay regular". (See SNL comedy skit "Colon Blow" for a good laugh.)