I’m not sure where you’re coming from in this discussion. Nobody is saying bribery won’t work in such situations.
But you do understand that the author is a journalist (1), and really just aiming to research for an article that presents some intriguing material, right? Not a roadside snacks competitor, with a large budget to spend on getting these sellers to exfiltrate supply chain intel.
(1) https://www.atlasobscura.com/users/mediabarkha?view=articles