WebComponents can do just a fraction of what React/Vue do, and it's just the least interesting parts. The encapsulation is great, of course, but it was already possible to have "reusable components" back in the jQuery days and before.

All the WebComponents usage I've seen professionally lately were wrapping React/Vue or using some other lightweight framework that does something similar.

Not saying WCs are bad tech: just saying I think there are some great ideas in Vue/React that still don't have a native API. Would LOVE to see a new version of WebComponents adopting some of those ideas (only the good ones though haha)!