To begin, please read this interesting opinion from David.
"Wait, wait, wait. What does the performance of persistent data structures have to do with the future of JavaScript MVCs?
A whole lot.
We'll see how, perhaps unintuitively, immutable data allows a new library, Om, to outperform a reasonably performant JavaScript MVC like Backbone.js without hand optimization from the user. Om itself is built upon the absolutely wonderful React library from Facebook."
- The Future of JavaScript MVC Frameworks
David Nolen (swannodette), 17 December 2013
http://swannodette.github.io/2013/12/17/the-future-of-javascript-mvcs.
At the time of writing (September 2018), Backbone is already out of business. Even the popularity of Angular struggles to compete with React. React took the market insanely fast and once it finally changed it's license...