20 years ago everyone was also sold OOP on the premise that inheritance was the best thing to ever happen to programming. Turns out people are wrong sometimes. And especially when they're being idealistic about things.

The concept makes more sense for styling simple document style pages from 20 years ago, but it hasn't scaled to modern designs, complex web UIs and responsive pages that we want to code now, which isn't that surprising.

> we would all be writing purely semantic html with completely orthogonal and swappable css. And today literally no one designs web sites that way - html today is mostly specific to presentation

I think of HTML + CSS as the presentation layer now, and the data lives in your e.g. database and Markdown files, so the data and its presentation are still separate enough.

The idea of just swapping out the CSS to completely restyle a complex site is nice, but people need to accept this hasn't worked out (and not because devs are bad at CSS) and move on.

If you're good, the same HTML serves mobile and web clients. It's a PITA to write, sure, but if that isn't CSS succeeding then I don't know what is. There's a ton of stuff I wish was different about CSS and HTML (and JS), but going from a small portrait device to a large landscape viewport with the same html? HTML does the HTML stuff and CSS does the style stuff. The fact that you have to tweak the HTML and CSS in a loop until it's right, in order to get to the finished state doesn't indight the fact that it's the same HTML for different clients.

a lot of semantic features like the document outline algorithm were never actually implemented by browsers so it was hindered from the start