If you have ever done the exercise where you whisper a short story to one person who then whispers it to the next on and on and on and then have the last person say what they heard it would explain what this article is speaking about perfectly.
At one point all of Gods children were told the story, but it changed in many cultures over time and got twisted into what we know today. Only the Jews were able to keep the story unchanged through time at Gods direct command.
The only thing really up for serious debate in Genesis is the time frames in regards to creation. Which can easily be explained by God being outside of our time and that the days mentioned in the biblical account of creation have no relationship to how we count a day.
And there wasn’t even a written form of the Bible available to the general public until what, the 1700s?
So how could you describe the story in a manner that could be spread through spoken word?