React speed when keeping your states and data in sync is that React makes all changes to the virtual dom then it makes it to the browser dom.
It not different then the concept of batching graphic changes in a 2d game. You blit batches of sprites that need to be changed around the same frame instead of making 500 draw calls you make 1.
Instead of the developer worrying about trying to gather all their dom changes dependent on user interaction and data syncing you interact directly with Reacts vDom and then react takes care of making the dom changes.
Virtual dom frameworks are a huge thing now cause UX/UI are more complex and we were fighting those issue before. Angular, Ember now, Vue, react ect cause we get speed back when making many state changes to our UI.
This has nothing to do with Atom.
