I don't know if Facebook has done any formal studies. Here's one way to think about it: if you have a webapp and have state in JS objects that you have to synch

I don't know if Facebook has done any formal studies. Here's one way to think about it: if you have a webapp and have state in JS objects that you have to synchronize with the DOM, that generally takes a fair bit of code. React provided an approach for eliminating synchronization code entirely. My own experience and that of the many others that created webapps pre-React and then adopted it is that its model simplifies our work and removes bugs. That's why we use it. It's also why there are a bunch of other vdom libraries and Ember and Angular have both moved toward similar one-way data flow models. There's a lot that we do day-to-day that doesn't have research to back it up. At some point, we have to try things out for ourselves to see how they work for us.