It is not at all obvious to me that a single page application requires more state than a multiple page application. Consider a choose your own adventure book.

It is not at all obvious to me that a single page application requires more state than a multiple page application. Consider a choose your own adventure book. Both a single page application and a multiple page application can implement this entirely through the url and I don't see how I have any state other than the url. If that is too facile, there were choose your own adventure books where you had hit points and could fight monsters. So now I store hit points in the session or in the url or in the single page application's state. Single page application doesn't mean single url. I don't exactly understand what additional state would be required to implement any particular user experience via a single page application or multiple page application. The only difference I see in either case is where the state gets managed and mutated.