You can sketch on a touch-enabled device which is not quite the same thing as people working things out on big conference room whiteboards.

That said, people could probably use tablets more systematically for sharing hand-drawn/written stuff in real time. Some of it is about adjusting to the realistically available tools as well. For large meetings where some people have to be remote, for example, we've switched things that we would have historically probably written on a whiteboard to shared docs online.