React has grown so powerful it isn't even just about the browser any longer. It runs everywhere. The browser has finally become a dumb pipe, something it should always have been. Web components are trying to reverse that, but you'd be ignoring innovation if you fell for it.
The extensible web is about low-level access. Web components go against everything that stands for. They're again pushing a bad vision that was decided on almost 10 years ago by people sitting in a closed room trying to interfere with how we write apps, resulting in a useless spec that adds complexity and weight. That spec btw took years of pushback against Apple and other vendors that weren't even interested in web apps rivalling their native stores. They have eventually given it green light because the spec is so tame it won't threaten a native app in a hundred years.
React on the other hand isn't much more than a simple idea:
const Component = ({ text }) => <span>{text}</span>
const Another = () => <Component text="hi there" />
The W3C has the worst kind of track record, don't expect anyone to fall for all this hand waving for "standards," no one is that naive anymore. If a spec doesn't perform it gets discarded and by this point we already know web component don't.