> If there was a load of cool software that Apple was preventing from coming into existence, Android would be the dominant platform by now, because it would have all the cool stuff.

A mobile application that can't be shipped on iOS has a much lower total addressable market, which potentially makes it so that it isn't a commercially-viable undertaking for the developer. When I was working in the mobile space, I saw more than one great idea that never advanced to a product because of this factor.

There are also a lot of cases where a cross-platform mobile developer will kill an otherwise promising feature because they can't ship it on iOS and don't want to fragment their product by having different feature sets on each platform.