> If the market for their craft was that large why do there seem to be so few of their projects left behind? Stone for building is comparatively rare, so build

> If the market for their craft was that large why do there seem to be so few of their projects left behind? Stone for building is comparatively rare, so buildings that are dilapidated tend to see their stonework reused for new buildings. If we're talking about 4000 year-old architecture that has gone through several eras of state collapse and rebuilding, then you'd expect to see lots of reuse. Note for example that the pyramids--even the great pyramids at Giza--are pretty thoroughly denuded of their outer casing blocks, and there are a few lesser pyramids whose outer structure have been entirely carted away.