People like the knowledge that they are not being ripped off by the person they are interacting with. On Uber you are essentially guaranteed that you are paying the absolute max that you would accept algorithmically, and the driver is getting the absolute least they would accept to drive for. If the balance shifts in any way, someone is ripping off the person they will interact with.

Since the customer knows less about how much things should cost, they are more likely to be ripped off. People pay a 30% premium to ensure that they dont feel ripped off alone.