Mmm, I work on a multimedia sequencer (timeline, viewport, etc) in the browser, it would be utter hell if the whole thing was put together via manual DOM updates in something like a Backbone View render function. I know this because when I joined the company, they were trying to do it in Backbone. For a project of that scope, this was a great way to introduce a large surface for error and maintenance (the project kicked off right when React was launching and Typescript wasn't public). Leveraging React as an interface to updating the DOM removes all of those concerns from your implementation work. That's a big productivity boost when you're trying to build a multimedia sequencer. More so when your team is junior-dominant.