“There’s nothing in the “traditonal” separation of concerns on the web (HTML/CSS/JavaScript) that restricts it only to pages. In fact, I would say it works best when it’s applied on smaller scales.” https://adactio.com/journal/14103
I think better building tools would allow us to separate those concerns (on both dimensions) while giving good, rapid feedback about how they work together. Building for a component library helps, but doesn’t get you there.