There’s some debate about whether the Exodus - assuming it was an actual event that follows the version spelled out in the Bible (not a small assumption) - actually took place under Egyptian rule or the rule of the Hyksos, who had invaded Egypt and ruled as “kings of Egypt” but only controlled a limited area in the Nile delta and were excluded from future lists of kings. (In other words, they labeled themselves Egyptians and pharaohs, but the Egyptians considered them invaders and usurpers).

The most important (for posterity) aspect of this debate is that the Hyksos capital was in the delta, which flooded yearly, and was destroyed after the Hyksos were finally expelled. Given the environment, the number of artifacts (especially written) that survive from the delta region is substantially smaller than those from middle and upper Egypt, where they were stored/found in the desert environment which is physically at higher elevation than the Nile valley and not susceptible to flood. Add to this the possibility that records, if they existed, might have been kept in a city that was destroyed in antiquity.

The final answer is that, whoever was in charge at the place and time where the exodus may or may not have happened (Egyptian or Hyksos) used writing as a form of propaganda. The Egyptians didn’t tend to record things in stone that didn’t go well for them: there are instances where battles that were lost were reported as victories, or simply left out of the record because they were losses and it did nothing to boost the ruler’s God-King narrative to broadcast that. So, in short, if the exodus were real, and a failure as suggested, there was absolutely nothing to be gained by sharing that information.

“Pharaoh died gloriously in battle!” Who’s gonna contradict that statement? They’re all at the bottom of the sea ...