For example of Kroger or any other retail store, the shopper doesn't have full visibility of buying options because the curation also happens before any product gets stocked on the shelf. E.g. the hidden retail-corporate-buyer-and-vendor relationships. Kroger example[1]. Costco example[2].
Because shoppers are not sitting in grocery chain's corporate headquarters to see what products the company rejects/prioritizes, they will still be influenced by self-interest of the retailer. Those are private negotiations of vendor contracts that influences what shows up on shelves so they can be as opaque as Amazon's recommendations algorithms. If Kroger wants to remove Kraft Macaroni & Cheese from the shelves and just promote their own-store-brand Kroger Macaroni & Cheese[3], the shopper doesn't really have any more agency.
[1] https://www.thekrogerco.com/vendors-suppliers/become-a-suppl...
[2] https://www.costco.com/vendor-inquiries.html
[3] https://www.kroger.com/p/kroger-original-macaroni-cheese/000...