Well, no. As much as I liked SGML back in the days for human-readability, having an SGML/XML/etc. parser is not the problem. The problem is understanding what the document is.

Today, much of the web consists of an empty DIV, populated with JavaScript from JSON objects. I can't do anything with that.

One step down, I have a structured, semantic document, but the semantics are defined as `class` elements. I can do more with that, but not a lot.

With HTML2.0, I couldn't keep much on the web, but it was semantic. I knew what body text was, what a header was, etc. Semantics are defined in the DTD, which is super-nice.

HTML5 points a path forward, with elements like `article` and what-not, but it's still got a ways to go before I can understand the content of a page in the way I could with HTML2.0.

There's a deep anti-pattern in there, wrapping things in wrappers, but that's a longer story.

That's vastily oversimplifying things. XHTML2 was a markedly superior language to HTML in a few ways, but you still would have needed to have the same CSS & JS components to interact with an XHTML page.