Nostr is the medium because it can achieve the first thing in theory.

In a market, competing entrepreneurs must be public (you want to sell a lot of things to the biggest number of people, therefore you can't be private). Increasing the privacy of customers can be improved to some degree.

If people are able to see cheap prices, that sends them a signal to buy and that can increase the opacity of certain customers and also incentivizes the producers around the world to keep competing fiercely to keep doing transactions through the amazon-like app without being censored.

This topic has a lot of interesting things to think but I don't want to get boring