Facebook released React.js as an open-source in 2013. Since then, the popularity of it was just emerging.
Many big names (Netflix, Uber, Airbnb, and more…) chose it, as it was easy to pick up, more convenient to operate with and gave them a lot of freedom in the interface execution. By that, they could deliver totally outstanding and customized interfaces.
After a while, React.js has been gaining more and more contributors, fans, and users. This is why it is still at the top of most loved and wanted frameworks to work with.
Last few years it totally overtook all the other frontend competition in popularity, mostly thanks to their extreme focus on user experience combined with development simplicity.
Today, it is the most recognizable frontend framework that enables not only developers, but mostly business people and marketers, to reach their demanding objectives.