I'm interested in these custom-element ui libraries, I think it's a neat concept. But I always get lost when they've got like… their own generic *-button element? And then an actual button in shadow dom?

I'm sure there's a reason for it, but how much reason? I get pretty drained by constant tooling re-inventions of basic html/css. I don't know if it's bad, but it smells weird.

Are there big wins in that wrapper, or just some default styles?