Avoiding those restrictions (including Apple signing apps) are usually the reason listed to start other stores. Why benefit would those other stores offer to anyone?
Why would prices be cheaper? How would the user interface be changed in anyway and how would it benefit users?
That's exactly my point. There are no real improvements I can see coming from any new store. Please explain how it will be better and why any actor would make it better.
One Apple employee acknowledged that in their discussions with Uber employees about their need to pay a commission on IAPs, Uber tried to convince Apple to remove their commission because that 30% would have to get passed on to customers.
However, I have no reason to believe that Uber would actually follow through. It seemed like a bluff. Certainly, any economic theory I'm aware of would have Uber and customers split that 30%, with Uber paying the vast majority out of profits.