It used to be that we web developers would first test our sites in lynx to make sure the structure was correct and then add everything else that graphical browsers could see and use. I still do but there are far too many who don't. Especially those who use canned packages like Wordpress, forum software and the like, and those who now create their pages on the fly using AJAX and, probably, anyone who uses Microsoft software. That's why some sites are very usable in lynx and other text-based browsers and, in others, it's almost unusable.