Climates can change drastically across even just a few hundred years.

As I presently understand it, the initially fertile Nile-inundation that flooded the banks with precious crop-growing nutrients on a regular basis (for example in the time of Rameses II) slowed over the years, changing up certain equations upon many things. For example, once a jungle area slowly shifted to a desert area… that was arguably one of the long-form primary causes for the collapse of the once-mighty Egyptian Empire, after some thousands of years of primacy.

(later counterpart of sorts– The Mayan Empire?)

And yet the Egyptian Empire was monumentally impressive in its prime, I would argue.