1. It's super popular
2. You can build anything!
3. It performs
Some of the most impressively fast sites on the web are built with React. It uses what's called the VirdualDOM to only re-render parts of the page that are changing. The developer experience also performs. It's component based, which makes it easier to split up complex user interfaces. The React team is also working hard to make it even better. They recently released React Hooks, and React Context which dramatically simplifies building apps with React.
4. Lots and lots of educational content online
The React community is huge, and there is no shortage of awesome content online to learn React - from beginner to advanced. I really like that I don't have to search very hard to find really high quality content. The course that finally got me over the hump with learning React is actually free on Scrimba! And if you haven't tried learning on Scrimba, it's super cool because pausing the video at any point drops you into the real code in a browser IDE.
5. Lots of open source goodies
More people are using React, which leads to more innovation and a better developer experience. There are more and more awesome dev tools, templates, frameworks, packages, plugins, etc. being released every day. Anyone who jumps on the React bandwagon gets access to them.
6. More jobs/people to work with
More React developer jobs are posted every day than any other language or framework. For job seekers, that's great news. If you're looking to build a team, that's also great news because there are a lot of React developers out there to work with.
I've really enjoyed experiencing the power of React for myself. After jumping into it, I see why so many people are excited about it. It really does make it a lot easier to build awesome apps. Now let's go build some stuff!