Only context I can think of such constraints being beneficial is if the document is only intended for printed (paper) output. Any other (electronic reader devi

Only context I can think of such constraints being beneficial is if the document is only intended for printed (paper) output. Any other (electronic reader device / software for example) use I can think of right now, it's better to have all the bells and whistles of font, style, color, layout adaptations readily and easily available for the end user.