Yeah, I'm not saying smartphones aren't good or significant. Just that they haven't replaced desktop-computing -- just added to it. The article says things like
"Android and iOS have replaced Windows in importance"
But Windows still seems plenty-important, to me. I don't see how one replaced the other, it's just that mobile is under more dynamic development right now because it's new.
I think web apps made desktop OSs much less important for most people; I don't think switching to osx would have really been viable for most people if it wasn't for web browsers/standards.
I read your comment on a mobile device, and switched to my laptop to write this comment. Two different operating systems, same internet.