IIRC, we have Egyption writings on papyrus going back to the mid-3rd millenium BCE.
I've heard claims that the global flood was supposed to have happened about 4000 years ago. Which begs the question- how did the 5000+ year-old papyrus survive submersion in water for 40 days or so?
More interesting to me is how saltwater fish and freshwater fish comingled. Whether the water ended up being predominantly salt, fresh, or an middling brackish, there are still thousands of fish and plant species with very specific salinity needs that should be dead today.
First of all, the rains fell for forty days and forty nights. The actual Flood lasted for a solar year. It might pay to actually read the text you are debunking.
Secondly, what papyrus? What are you talking about? Are you talking about the Torah Scroll from which the story of Creation and the Flood come? That wasn't papyrus but animal skin (all Torah Scrolls have to be written on animal skin), and it was written by Moses at Mt. Sinai, where G-d dictated it to him letter-for-letter. Perhaps you would like to make a remark about that?
G-d dictated the portion about Noach because of the Noachide covenant with all humanity. He dictated the account of Creation only to refute the Nations of the World when they accused Israel of stealing the Land from the Canaanites. Bet you didn't know that either.