If you're good, the same HTML serves mobile and web clients. It's a PITA to write, sure, but if that isn't CSS succeeding then I don't know what is. There's a ton of stuff I wish was different about CSS and HTML (and JS), but going from a small portrait device to a large landscape viewport with the same html? HTML does the HTML stuff and CSS does the style stuff. The fact that you have to tweak the HTML and CSS in a loop until it's right, in order to get to the finished state doesn't indight the fact that it's the same HTML for different clients.