The key benefit of React is an extremely low cognitive load. There are only three simple concepts to grok (props, state and lifecycle) to get productive. The code is very easy to reason about (components are essentially pure functions of props and state) and debugging is much simpler than with vanilla JS or jQuery on a project of any meaningful size.
With respect to performance, React shines when it comes to DOM mutations (e.g. removing a div from DOM, creating a new div, inserting new div into the DOM) which is what you generally encounter with the real-world load. Here is a demo illustrating such load [3]. Benchmark offered by OP is amazingly contrived (actually it feels designed to show React in a bad light and lack of full source code is very telling). I struggle to think of a real-world scenario of append-only page with 1000+ images in the DOM, there is simply no valid reason to do that. React in turn makes it really easy and fast to implement infinite scrolling (similar to UITableView) and there are a couple of good open source components that address that.
[1] See the bottom of https://aerotwist.com/
[2] https://aerotwist.com/blog/polymer-for-the-performance-obses...