This is wrong on so many levels :-) As of now, React is probably the only major frontend framework that doesn't interop well with web components, requiring various hacks for doing so. Proper support is hopefully coming in version 19. What you have with React is its own, React-specific way of encapsulating parts of UI into stateful functions that helps to think about them as components.

And to have web components support built-in would mean to have them in the browser anyway, not in a third-party library.