The problem here is... just viewing the picture is creating a 'demand' for such material, and therefore a supply must be created, which exploits minors. I'm not really on board with the drawings of such things being forbidden as well, that seems like overkill to me, and drawings may supply the consumers of such materials that aren't exploitative of minors. It's an ugly nasty situation for sure.
You're saying people have sex with children just to get some high fives online? It's illogical on its face. They might be more likely to record it if they're already doing it, but that's about it. Commercial transactions are an entirely different issue. Also, some people enjoy watching children beaten and brutally murdered. But that's legal (as long as the child isn't naked) to possess pictures/videos of. People get off on adults being raped too, but videos of that are legal. If viewing encourages the act, why aren't things like that illegal? Or maybe we should arrest anyone who has adult porn they can't find signed affidavits of affirmative consent for? The laws banning CP were created when most of it was purchased. When that was no longer the case they made up other rationales with little evidence and zero discussion of whether such a thin link was worth a massive infringement on freedom (destroying someones life because of data they possess) because why on earth would LE ever want to give up the massive power and carte blanche to ignore half the constitution that came with it. If it was really about protecting victims of crimes or that viewing encouraged crimes, a whole host of other things would be illegal.
You mentioned cartoons filling demand, but that doesn't go far enough: some studies have even indicated legal possession of already-created freely acquired CP (i.e. no realistic contribution to market) can actually satisfy a pedo so they don't go out and actually molest a kid, at a better success rate than completely abstaining from viewing such images. However disgusting CP is, if it prevents pedos from becoming child molesters at a higher rate than it encourages them to, the net result is less children hurt-- and that should be the goal, and right now it's not: we're far more interested in the low-hanging fruit of viewers.