It's possible to write PDFs that don't "work" (for some useful definition of "work" similar to the case with HTML) offline. Please stop pretending that's not true.
The reason offline utility tends to be true more often for PDFs is that PDFs are not generally regarded as the preferred online-default format of choice, which is in turn a matter of social effects rather than technical capacity. Reverse the socially accepted roles of the two document formats and watch the same complaints get made against PDFs as you're making against HTML. I'd bet money the "normal" state of affairs would remain the same in terms of the perceived benefit/detriment allocation between online/offline formats; only which format was considered which would have changed.
. . . but then all the web would be even heavier documents, and even less customizable for local viewing, thanks in part to that pagination and strict formatting situation.
It's possible, but it takes work. I can't remember the last time a pdf did something unreadably weird, usually my only gripe is with something that's a scan of an old document but whoever turned it into PDF didn't do OCR.
The reason offline utility tends to be true more often for PDFs is that PDFs are not generally regarded as the preferred online-default format of choice, which is in turn a matter of social effects rather than technical capacity. Reverse the socially accepted roles of the two document formats and watch the same complaints get made against PDFs as you're making against HTML. I'd bet money the "normal" state of affairs would remain the same in terms of the perceived benefit/detriment allocation between online/offline formats; only which format was considered which would have changed.
. . . but then all the web would be even heavier documents, and even less customizable for local viewing, thanks in part to that pagination and strict formatting situation.