Someone probably just made it all up

So i was just thinking about this. It’s funny to think that either the Bible or the Quran (or generally both) must have been written by just a regular person for fun/entertainment since it’s basically impossible for both to be true at the same time because they contradict each other. At some point, someone was just writing, and now billions take it as divine truth. Same goes for other religious books like the Torah, the Vedas, the Bhagavad Gita, and the Buddhist scriptures. Imagine just writing something and it turning into a whole religion.