The myth?
" Evidence suggests 6th century BC."
That's when the Babylonians pillaged Jerusalem and hauled the Jews off into captivity. That's when their books would have been destroyed along with the temple. I don't believe that story about Sargon. It's likely the Babylonians ocpied the story, not the other way around.
Yes the myth that God dictated the books to moses word-for-word. However, scholars seems to agree that the Five Books of Moses were not written by one author or in the same period,iirc.
That's when the Babylonians pillaged Jerusalem and hauled the Jews off into captivity. That's when their books would have been destroyed along with the temple.
I believe there is evidence that the oral tradition was reduced to writing c. 6th century BC, while in Babylonian captivity. Idon't think the OT speaks of any destruction of the scriptures, but only of the Temple.