It may help if you didn't only look for information on such things from pro-aethiest /anti-religion sites Thorne and instead stuck to academic sources....your so far off base claiming the Exodus is completely fictitious and couldn't have happened it isn't even funny.
Is it contested? Yes.
Why is it still contested?
There is a long standing schism between the narrow minded fuddy duddies in the field who simply can't stomach anything in the Bible as being construed as right and a much more open minded group who has often found a root of truth in most myths and legends of the ancient world.
I would put more faith in the open minded group if I were you...afterall...they discovered whats now commonly believed to be Troy, the Hittites, Babylon, perhaps even Atlantis and the most likely site for the Garden of Eden itself etc etc.
And all with fully supported cross disciplinary peer reviewed science!
Early mistakes in interpretations of the dates in the Torah lead to a narrow focus within the field to search for evidence in one very narrow window of time.
Collaborating data from other periods however (proved the earlier assumptions about the dates were indeed wrong) and corresponding periods have shown that a group of non-eygptian people did in fact live in lower Egypt and left during a time of well documented great calamity (most likely brought on by the eruption of Thera in combination with a terrible series of droughts and other terrible things some of which match the "10 plages" in great detail ) who subsequently migrated into Cannan (becoming a huge well documented pain in their assess instead).