That seems like an unfortunate tool to have discarded. Right now, I can use vertical separation to structure text, but horizontal separation.... Well, that's far more limited.

Within sentences, there's the dash—either em or space-en-space, depending on where you're from—and there are plenty of other structural options. Between sentences, you've got the ellipsis, and that's it. The way they're used in the Declaration, in place of paragraph breaks, is helpful even when you're not just trying to save space—for example, to structure a list of short words or phrases without creating the visual separation from the text that comes with using separate lines.