It seems like from the first crude cave paintings to the statues of lugals in Mesopotamia, that the goal was not a realistic depiction of the subject, but rather a stylized representation. As far as I can tell, truly realistic work didn't begin to appear till much closer to the common era, and it doesnt even particularly seem like ancient artists were trying to be realistic.

Are there any theories as to why it took humans so long to pursue realism in art? It seems like it would be an obvious target to represent what you see as accurately as possible. If I'm missing info or appearances of realism here, please correct me, I'm having trouble researching this.