I think the (misuse of) so-called "separation of concerns" has been the most harmful thing that happened in web front end development. HTML can CSS are the same kind of concerns: the presentation layer. The idea that HTML is purely semantic and has nothing to do with presentation is just burying the head in the sand.

Separating HTML and CSS into different files is just like separating a bunch of methods/functions into different files, or splitting one monorepo into git submodules. Yeah, it sometimes makes sense, but if you're doing it for the sake of separating things then just stop.

I think the only point of Tailwind is to make front end devs realizing how much separation of concerns is misunderstood and misused as a dogma. Once you realize that you can ditch Tailwind if you like.

There are different types of separation of concerns :) https://x.com/simonswiss/status/1664736786671869952