That all sounds great until you start considering what needs to be done for accessibility. For blind readers as well as many different screen resolutions.
Better is if the document specifies the text (and any appropriate annotations, e.g. how to pronounce), and the blocks/sections/etc, and then the client software can display it according to the user's settings. Whether that means you want to display it on the screen, with your own formatting, or use a braille display, or text to speech, or whatever else it might be, you can use it.