Markets only work in well-regulated environments, this has been known since forever (Adam Smith).

There is no meaningful competition in a marathon if I can drive you over with a car at the first 100m.

And thanks fkin God that we have regulations and meaningful laws and some asshole for-profit company can't just put drugs into food.. the "informed buyer" is bullshit. Humans are faulty, and there is a billion dollar industry meant to take advantage of said faults: it's called marketing.