Why did God destroy all of humanity other than Noah when he knew some of Noah's descendants would also be evil?

Genesis 1-11 is the narrative of how the earth went wrong.

Ben thinks many flood narratives exist because similar myths formed in different cultures. Then similarly to the Creation story, the Biblical flood narrative was co-opted from pagan stories to show Jehovah was superior.

Matt thinks there are many flood narratives because they're all remembering a historical event.

Ben says it would be nearly impossible for oral tradition to preserve the original flood story. I think it's fair to say it would require a miracle.

Ben thinks Noah's sacrifice is the Levitical system being reflected back into the story from the later story tellers.

Fiction shapes us in a subtle, deep way.