Web 2.0 and what it changed
Web 2.0 changed all that by turning the pages themselves into the web application. Without the GUI being part of the server-side code, web-applications are simply services that supply and consume data. And that data is, increasingly, being sent and received in JSON format. What need of the controller now? The funny thing is, the MVC paradigm was revised to cope with Web 2.0 as well. A sort of "web-incunable" – an incunable being a 15th century book that aped the design of manuscript books in type. In the same way, MVC is a kind of desktop application being aped in web applications – trying to do all work in a single place, when the separation of the model and the view is already implied by the Web 2.0 application model.
15th Century print incunable (manuscript lookalike)
Doing (almost) everything on the client
An extinct dinosaur
Won't that slow down the client?