In terms of the erosion, doesn't wind erosion on raised surfaces behave very similar to how water erosion on shores behaves?

Since both are just fluids brushing up against surfaces, and the fact in the desert the wind will have a lot of silica dust in it, it stands to reason the wind currents around the pyramid would have very similar erosion patterns to water on a shore.

Fluids are fluids, air doesn't behave to dissimilar from the ocean, and wind is not to dissimilar from water currents in terms of the physics.

Silica dust will kick up off the nearby dunes, carry in the wind, but due to its weight it'll be less likely to erode higher elevations. So the tip top of the pyramid is high enough up sand in the wind won't reach it as easily so it erodes way slower.

Much akin to how waves crash on a coastline, water has weight so the higher an elevation is, the less and less sea spray it gets hit by, so it erodes slower.