React can be written with ES2015, the latest version of ECMAscript. This makes applications written in React ready for the future. React also accommodates thinking in components, which for example is reflected in Web Components, a future HTML5 standard.
Most web applications become harder to maintain as time progresses because the complexity increases. React consists of reusable components, which assures consistency in behaviour, presentation and usability.
React goes further than just HTML. It is not only ideally suited for development of web applications, but native iOS and Android application interfaces are perfectly suitable to develop with React as well.