>what makes 2D so appealing?
1. Childlike features. Nature made us like them as a motivation for parenting. Imagine children were just dumb annoying and furthermore ugly small goblins. Current idealistic values of our cultures are different thing, people of the past were cynical.
2. Idealized characters. Their actions, poses, lines, looks, all of that is written by experienced old men, all these traits undergo the evolutionary processes and selection in the wild, at the Japanese market (they also conduct surveys, etc), to give birth to the most powerful moe monsters.
3. It exploits bugs of human visual perception. As there are 3D lolikons, some people are not affected by it and hates animu art. Evolution need some genetic diversity.