I've heard it said that we could not reproduce the pyramids of Egypt with modern technology. Is that true? From what I understand they went up faster than we could assemble them. Is that true?

Thanks.

No... people are too lazy. It takes a LOT of work. And a lot of people to do that hard work... either by choice or by threat of death.

It probably took 20 - 30 years, using 100,000 slaves, according to Herodotus.
Estimates for now are around 5 years. Yes, it's technically possible. Still a marvel that they were built with ingenuity. Ramps, water as a slippery base for moving stone, and so on.