Is it possible to one day replace the privacy nightmare of Amazon with a decentralized merchant network? All I really use Amazon for these day is aggregate customer reviews by query, then buy the items as direct as possible. Why can’t respectable tools to this instead? I understand the cost, but could the tech be adopted?
Amazon is as you said extremely efficient on their warehouse and shipping because of their centralization and size. They can build extremely expensive warehouse to keep being efficient and surpass the competition.
There would maybe be possible to get an “enhanced” activity pub in order to protect privacy and financial informations. There is already something similar but without activity pub : a multitude of website where it is possible to buy things.
But there still needs to be some centralization, either through the postal service for small companies, or through centralised warehouse companies, with spzcialized equipments. And both of these things are already in place.
However if the OP wants a decentralized Amazon like efficiency, it won’t happen. The costs will increase and it will take more time, because the way the shipment will work will heavily depend on the seller.