I just have a simple, obvious point about xkcd: It’s not a webcomic. It’s a series of consciousness-raising graphs, with some comics thrown in to kill time during the intense creation of said graphs.
For instance, today xkcd has mapped out the U.S. economy at five orders of magnitude. It’s impressive and informative. “Cartoonist” Randall Munroe points out both factoids (Coke could literally buy the world a Coke with their marketing budget) and fundamental insights (the 400 richest Americans are worth more than the poorest 150+ million).
And that is OK. I just think we should reclassify xkcd from “webcomic” to “what ‘infographics’ should actually mean”.