> Notice also the thing the customers should be doing in response to the second one: Sharing the prices they're shown for everything with the other customers so they can arbitrage by having the person offered the lowest price be the one to order it.

Ah, but this is worst in industries where resale is not possible. For example, flights, digital games, and rideshare. Of course one has the option to just not fly, buy games, or use Uber, but this limits a lot of convenience and function in a modern society. This is why I think targeted regulation is not such a bad thing - provided, as you explain, that the reason for the price discrimination is not because the customer actually costs the business more.