Genesis is not the only book of the bible which has no scientific basis but Exodus as well fits into the category of historical allegory.

The Egyptians kept meticulous records of all their history even down to trivial details.

Nowhere is there anything mentioned about Hebrew slaves. In fact nothing mentioned about slaves building pyramids or anything else for that matter.

Nothing in archeology has been found to place the Hebrews in Egypt at anytime in Egyptian history.

Bible historians now agree that Exodus is simply a narrative providing the Jews a historical framework. But in fact is pure allegorical storytelling which incorporates evil in the world in the person of Pharaoh and makes the Egyptians the national enemy.

Based on my own research , I believe this was done to gain favor with the Persians who awarded them the land of Canaan .