Interop isn't just an issue between components, but an issue between the browser and components, crawlers and components, and of course all the thousands of JS

Interop isn't just an issue between components, but an issue between the browser and components, crawlers and components, and of course all the thousands of JS libraries out there. What's great about Web Components is that they don't need custom developer tools. The DOM tree _is_ your component tree, the browser naturally highlights custom elements, just like built-in elements. Editing the DOM and CSS just works. Placing an element into a temp variable and setting properties just works.