I think unless there are massive improvements to the developer experience the best hope for web components is as an implementation detail for a higher-level framework.
For me, I've been bitten and I would pick web components over a fixed framework for a clean sheet project. I don't think many devs have really tried to work with web components or they might get the bug, too!
PS: I wrote an intro series on this topic on Medium[0].
[0] https://medium.com/gitconnected/getting-started-with-web-com...
That said, having taught some introductory web development courses in the past few years, I sense that new devs entering the industry are interested in simpler solutions and not particularly keen to get into React. The React learning curve is much steeper than it once was now that it has so meany features and the benefits are not so clear to someone who is starting from scratch.
You don't need it. Do devs these days even know about Web Components and shadow DOM? You can define per-component styles now with CSS selectors to target any child elements within the component and you can do it in such a way that the styles are contained within the component... And for cases where you want to inherit styles, you can just use the regular light DOM.
All these frameworks are re-inventing the wheel and making it worse. Or it's like attaching a horse to pull a perfectly good car.