Regarding those so-called "Pillars under Khufu pyramid" that are apparently supposed to be a power generation system, amongst other things ...

My first thought was "They built 2 kilometre high columns? That means they had to dig down over 2 kilometres - through limestone - before they even started building the columns. How did they lift the spoil out? Where did they put it?" It was a very short step from that to "Ah, bullshit!" 😂

For reference, an excavation volume of 251 x 251 x 2,186 yards (base-of-Khufu x 2 Km deep) would shift 137,720,186 cubic yards of limestone. That would weigh roughly 275,440,372 US tons (1 yd³ is approx 2 US tons).

Questions for extra credit:

How long does it take for a person to climb down a 2km-long ladder?
How much longer to climb back up after digging all day through limestone?
How did they see while working?
How did they get fresh air?
How was food and water provided?

*Apologies for the mixed Imperial and metric.