> just getting their act together and hiring a few developers to build a basic app.

Developing a new app each time sounds like a very expensive way to go. If that allows them to beat Uber then Uber is in trouble in this market. Because the next step is to create a service that any restaurant can join for fixed payment. Even with customization marginal cost for such thing should be quite low, surely lower than everybody building their own apps from scratch and maintaining them over time. And that's pretty much what delivery companies offer? So how developing your own app would be more effective than just using already developed app and adding a couple of menu items to it?