Consignment is still a stocking risk. They are on the hook for holding costs. Amazon doesn't do shit with marketplace inventory. Sellers are either stocking it

Consignment is still a stocking risk. They are on the hook for holding costs. Amazon doesn't do shit with marketplace inventory. Sellers are either stocking it themselves, or they are explicitly paying amazon to hold it in their inventory. The difference matters because retail stores always have an incentive to sell the things they stock. Even pure consignment stores will refuse to consign items that they don't think they can sell. Amazon has zero incentive to sell marketplace merchant stock, as they bear zero cost to not sell it. So anytime they start to compete against their merchants, they can effectively hide competitors listings in a back room out of sight and never have to deal with the consequences of doing so.