Every religion has a sacred duality which is central to the mysteries of that religion. For Christianity, it is good and evil. For many religions, it is spiritual/mental/emotional and physical. For Wicca, it is male and female. These sacred dualities create ripples in the fiction of the cultures which practice them.
No matter how we try to escape it, we live in a Christian culture, and so the primary duality of our fiction is of good versus evil. An evil galactic empire versus a good band of scrappy rebels, a killer versus a detective, even a little girl on her way to gramma’s house versus a big bad wolf.
Now, let’s compare this to the fiction from pre-Christian cultures. The Sons of Tuireann were being punished by Lugh, but Lugh wasn’t evil; he was asking for repayment for the death of his father. Loki may have caused a lot of trouble, and even murdered Baldur, but he isn’t described as evil until very late in the story. And the morality of The Twelve Labors of Heracles is so gray, it’s almost easier to call Heracles evil than Hera.
So does fiction really need a villain? Or is the villain a mostly Christian concept which has taken over literature because of our preoccupation with good and evil?