You might be surprised to learn that not all challenges are purely technological. The biggest challenges with such megaprojects are political, economical, and social. A Wikipedia clone is completely worthless if nobody is willing to contribute - it would just be an empty database!
As an aside. When the Eifel Tower was built it was considered tacky by many and assumed to be temporary. Maybe some of the most remembered things of our time will be taken for granted. Maybe some huge data center will be a museum.
Why doesn't it? The owner isn't buried in it?
> The biggest challenges with such megaprojects are political, economical, and social
Indeed; this is why we moved on from piling rocks in a formation that didn't fall down easily, and put all those things you list into cathederals, hydroelectric dams, the Apollo missions, etc.
Several hours later, I realise we have many things which would seem like much more impressive versions of the pyramids, in the event of the collapse of industrial civilisation followed by a second renaissance and future archeological digs looking at us as we looked upon the tombs of Tutankhamen: artificial hills made by covering landfill likely contain a lot more precious metal than a pharaoh's tomb.
Isn't that the point of TFA and this whole conversation?