From my perspective, a DjVu or PDF file is just an archive format for
images. Any text that comes along with them is ancillary; if it's missing, we can always generate it from OCR. I could just as well use CBR/CBZ files, though they're not as reliable for having a sensible format. I want to avoid, as much as possible, dealing with a bunch of disconnected page images, because that maximizes the possibility for human error.