I know it’s a nitpick considering your larger theme is the evolution of storytelling, but I have to respond to this: “Mobile is not a platform, each app within it is.”

The rise of notifications and their ability to reach inside and across apps, and infer context through sensors and act on that information, makes mobile OSs platforms in their own right. The degree of control over these systems that they allow users is rapidly becoming a key differentiator between iOS and Android.