There is a great conspiracy that says This was not from wind, sand, rain, stone scavenging. Khafre pyramid at Giza was under sea for a very long time.

Karst undercutting erosion of the Tura limestone cap of the Khafre pyramid at Giza. The erosion turns up parabolically at both ends, characteristic of wave-action induced seawall erosion at 90 degree corners in harbors and ocean breaks.

The Khafre Pyramid shows signs of erosion that seem to have been caused by seawater. The limestone used in the pyramid’s casing (Tura limestone) is vulnerable to erosion when exposed to seawater, while the limestone used in the structure itself (Mokkatam limestone) is more durable.

The erosion patterns match what you’d expect if the pyramid were submerged in seawater with waves averaging about 6 to 8 feet high. The water level responsible for this erosion is thought to have reached a height of 576 feet above sea level.
This erosion is centered around a specific height on the pyramid, which suggests that it was caused by a large-scale flood or inundation, either global or regional.