[Andrex]

> Shadow DOM seemed like a tightening/winnowing/control thing

This is useful when you need to apply constraints on teammates, same as applying a linter to your project's CSS. You need to guarantee your internal components work well together.

If your style is more "make a component and throw it over the wall for people to use," making everything "public" may be a better approach.

But most web components will never be public or shareable, and that's OK.