Some archaeologists, and myself, hold to the theory that Exodus is actually a folk memory of the Bronze Age era Egyptian imperial hegemony over the southern Levant. The people archaeologists can identify as being distinctively different from other Canaanite groups began to emerge in the central Judean hill country around 1200 BCE, and their settlements and inscriptions can be traced as distinctively “Israelite.” This is called the Israelites as Canaanites Theory. Exodus came into the form it is because the Biblical authors needed it for the cosmology they were constructing, and they borrowed extensively from Near Eastern literary tropes (the Baby With a Destiny Found in a Basket in a River, for instance) and Israelite folk memory in constructing it.
If you put the Books of Exodus/Joshua and Judges side by side and really read the texts, you’ll see that they tell the same story. One tells the story of an exiled people making their way home after so many years and violently reclaiming the land via military campaigns which left dubious archaeological imprints, and one tells the story of a loosely organized Iron Age tribal society sharing the same general folk religion and language gradually emerging and gaining power over other Canaanite groups, including the ones which were theoretically wiped out in Joshua.
….Biblical Studies was my jam in undergrad.
Further Reading: http://historicity-was-already-taken.tumblr.com/Further%20Reading#Biblical%20Scholarship