As a developer from 2005 or so onwards, I have only ever known the Markup + Stylesheet system, having read a huge number of articles, where it was touted having

As a developer from 2005 or so onwards, I have only ever known the Markup + Stylesheet system, having read a huge number of articles, where it was touted having the document markup separate from the styling was the holy grail of web design and productivity. Nowadays, I see mixing of styling and content to be all the rage, which I actually feel is easy to use. Of course, component systems still split out the styling and document markup, but the line, and developer thought procress is a lot blurrier. I would love to know if there are any better systems of presentation, compared to the document + markup paradigm.