Well, yeah, but you seem to be confusing the authenticity of the writings as ancient artifacts with the historical accuracy of the contents of the writings. I don’t think anyone disputes that the Torah contains stories that had been widely spread and believed among the writers, compilers, and intended audience at the time.
Come to find out that so many of these myths were not actually true: that they were legends built through the centuries to fluff up the importance and gravity of the United States in the eyes of naïve schoolchildren.
It was with some sadness that these myths were dispelled for me, but no less a sense of wonder to learn what had actually happened in this relatively recent history. There is still plenty of room for myth and legend in the popular imagination.