The reason they never left robots to maintain the pyramids or if they did
they have long since rusted away to dust is the fact you can't maintain
technology without people, and technology as we know it is still reliant on
human infrastructure and is in our World a result of a Capitalist Feudal
system, and the whole tower of Babel is reliant on every other part, and we
still have people living in the stone age, we have to have some people
living in the stone age, because they create the resources for the next
stage of development in the system and so on.

Look, the whole Von Neumann concept is that machines replicate
according to a genetic template. They can also repair again according
to that template. Biuological organisms have DNA, VN machines have
information stored on some medium or other. A VN genome is protected
using Reed Soloman, or other error correcting code. That is the basic
concept. This last contribution of yours seems to hint at Intelligent
Design. If what you say is correct- personally I think it is arrant
nonsense, it would imply that life is "irreducibly complex". If life it
NOT "irreducibly complex" maintaining a pyramid/sphinx in sunny Egypt
where energy is readily available is a totally manageable task. If you
can't do it you should not be thinking about interstellar travel. An
interstellar journey depends on Reed Soloman, it depends on constant
renewal of the spacecraft against radiation and other damage in a long
time frame. Removed from the vicinity of stars you need a
nuclear/antimatter process of some sort thoughout your journey. Indeed
spacecraft destined for thye inner solar system use solar energy, those
destined for the outer use a Pu240 isotope generator. There is plenty
of Silicon and Aluminium in the sands of Giza as there is on the Moon.

I have portrayed the VN machine as an inevitable result of
understanding CAD/CAM and basic Engineering Physics. Everthing these
days is on a CAD system of some sort, even cloths. If we understand
CAD/CAM we can perform the full range of human manual functions.
Intellectual functions, including working with ProEngineer and AutoCad
is another matter.

I will end by looking at how the Pyramids (and Easter Island) were in
fact built. I am a regular viewer of "The Time Team". They were built
with simple chipping tools. It took them a long time to do it, but
stone thipping, and dragging by teams of people will do it. A
cautionary tale. The inhabitants of Easter Island used up all their
forests, and could not afford to continue statue building. Society
disintegrated.

There is one point that can be made about "The Time Team". A VN machine
on Earth would simply represent the extension of automation technology.
It would mean that places like Thailand no longer enjoyed a cost
advantage over the US and EU as the manufacturing labor cost shrank to
zero. In space the TT is relevant in that their simulation could help
to reduce VN seed mass. You don't need a high level of technological
sophistication for electrcity, you do need the knowledge of how to do
it. We ought in fact to be looking at how chip making and chip making
machines can be produced from first principles.