The magic of the existing hourglass model, and the entire premise of the end-to-end principle [1], is that you can build all those features on top of the infrastructure provided by IP. IP as the skinny neck allows service providers to focus on delivering one thing very well, and enables anyone who wants to use that infrastructure to build anything they can think of on top of it.
[1] https://en.wikipedia.org/wiki/End-to-end_principle