That's the preferred format for advertisements because PDF is now a prepress standard which replaced EPS. For articles, the standard is formatted text that the dtp jockey can import/link.

You seem to think page layout applications can't link to documents to automatically update when they change. This wasn't the case when PageMaker was still a thing, and I'm talking the 1990s here. That functionality was there for this exact reason. Note that the document itself does not require any kind of "change control;" it applies to images as well as text. I'm not even certain what you think you mean by "change control" insofar as a standard text format's not going to have some kind of diff metadata in it.

HTML/CSS does not do gradient fills on text. An academic document markup language two decades old still has no native markup for math, cannot horizontally condense or stretch lettering, bullets are limited to images or prebuilt categories, and text justification has no conception of hyphenation despite most browsers shipping with dictionaries. Kerning does not exist; in fact typographical rendering is so unreliable that experimental specs are being tested in CSS to control it more strictly.

To paraphrase what you said, it's not (and was never meant to be) a page description language. The pros are that it by design scales, the con is that it is still too unsophisticated to render much more than blocks (and I do mean blocks) of text alongside blocks of media. We could be doing much better but the painful fact is that the W3C does not go out of its way to hire graphic artists to develop spec.

As a designer, I work with the compromise that my pages display in the intended way but do not prohibit user styles from altering them. That's what responsive design's supposed to do.