Comment by ozim
Yeah there is a lot of idealism in the project - problem is reality doesn’t care about your idea of separation of concerns and most likely your web applications will not benefit from it.
What I mean React and other frameworks went with mixing concerns because of reasons that were practical - for example realization that usually one dev implements HTML and JS code in one task, not like article comes up with designers and devs. In reality lots of designers don’t live in agile sprints and the same repositories as devs there is huge impedance mismatch.
The "separation of concerns" point is very overblown, IMO. It seems to have become a slogan repeated without considering what the goal is, and just completely dismissing components as another valid way of organizing code.
Components have won for a reason - for any given web-based UI component to work it needs to render HTML, to style that HTML, and logic for rendering and behavior. So HTML, CSS, and JS.
It only makes sense to colocate those things so that they're easier to build, understand, distribute, and use as a unit. Often times they're not even separable as the HTML depends on state and logic, etc.
And the weird thing is that any other UI platform has components that combine rendering, styles, and logic together and no-one bats an eye because it would be very odd and cumbersome to do it any other way, but on the web some people think components are bad. And they tend to provide no realistic mechanism for reuse except to use an external system.