Ya. One needful use case was (is?) variable data printing, allowing mass customization, like direct mail. Pretty much the same technical progression that happe

Ya. One needful use case was (is?) variable data printing, allowing mass customization, like direct mail. Pretty much the same technical progression that happened in user interfaces going from absolute coords and static layout to dynamic layout managers. The fix was so easy. Just retain some of the source document's meta data, eg this group of glyphs are a "paragraph". The PDF object model was explicitly designed for exactly this kind of extension. IIRC Some specialty vendors had some goofy work-arounds, like a post process tool for manually marking paragraphs. But Adobe could never be bothered.