Sure, but presumably the Sumerians also had a long oral tradition predating writing. It is just that we don't know anything about oral traditions thousands of

Sure, but presumably the Sumerians also had a long oral tradition predating writing. It is just that we don't know anything about oral traditions thousands of years ago, since they leave no archeological trace. What we can know about is what is written down on durable material, and Sumer happens to have some of the very oldest surviving writing. Stories are probably as old as language, but this is pure speculation.