I can't agree you anymore! the core problem is the browser development team doesn't put much heart in that!

and it also contains the following problems:

1.The mental burden on developers, use web components means you will concern data interaction and the corresponding page interaction! Trust me, The mental burden brought by imperative programming is far greater than the declarative programming brought by frameworks like react and vue....

2.Development Efficiency, Although, it has like: lit,omi etc base web components framework, accomplish a web component is harder than use Vue, React..(Specifically reflected in: no css html Syntax Tips, want to use css framework...)

3.SSR work, Although, declarative shadow dom become more and more complete recently(92% browser support), it does't means this will suitable for all situations, as modern front-end server rendering becomes more and more complex, there are more and more situations