The key issue is that mobile apps tend to be task oriented. A lot of web companies (like FB) are not transitioning into app studios by breaking down a monolith

The key issue is that mobile apps tend to be task oriented. A lot of web companies (like FB) are not transitioning into app studios by breaking down a monolithic site into set of mobile apps that deliver a single feature/accomplish a single task. If the open web were to be redefined along those lines, I dont see why users wont use that.