We also have the supplement market to judge how such a market would work. They're not subject to FDA approval, and are subject to false advertising laws. Websites can catalog and evaluate efficacy. So do they?
No. The market is a wild west of unsubstantiated claims, impure product, and (at the margin) unrestrained fraudsters.
If you want a preview of what this ratings-website environment will look like, Google "best cat food" and then try and figure out which advice is best.
DLU is a hard movie to enjoy if you’re actually worried about existential risk.
Every movie based in reality is hard to enjoy for the experts in that field. I work in intelligence, and can't take spy movies seriously. My wife is (among other things) a chemist, and can't watch forensics scenes.
The US nutritional supplements market is worth about $50B/yr (source: North America Dietary Supplements Market Report, 2021-2028 (grandviewresearch.com)). No website is even suggesting they perform evidence-based efficacy analyses. At what market size do you expect to see that?
Correction: originally gave global market size