Man, I always wonder what would have happened if Bill Watterson had been around for the era of webcomics. Much more creative freedom, and no editor or syndicate to tell you how to layout your panels. Would he have loved it? Or would he have hated it? He certainly wouldn't have wanted to build a website for it.
For me, it's hard to imagine him giving up the printed newspaper strip's connection to the physical world. Calvin and Hobbes is filled with references to the basic elements of physical reality: dirt, rocks, water, snow, speed, collisions, temperature, light, sound. Webcomics exist in a world of pure information.
Webcomics exist in the physical world because they appear on screens, which are just as physical as paper. Neither newspapers nor screens usually come into contact with dirt, rocks, water, snow, or collisions. Newspapers make more noise than screens, but screens emit more light. Printed cartoons exist as pure information too, in the sense that they can be copied and printed on different things.