I think one of the purposes of the pyramids was to be a sort of ancient beacon. The stone reflected the sun and moonlight, making it pretty tough to get lost. In the days of no GPS or electricity, I'm sure this was of great importance.

Have you ever been playing Minecraft and wandered too far from base before building a bed and just had to abandon that base until you find it by accident later? Imagine that IRL and you can't just build a new base real quick