Actually, we could. But no one would be willing to pay for it.
The Great Pyramid of Giza was built around 2600 BC.
By the time Cleopatra, the last queen of Egypt, died, the pyramid was already over two and a half millennia old. It remained the world's tallest building for about 3800 years, until it was dethroned by Lincoln Cathedral in 1311, although in other respects it dwarfs the Cathedral and most modern buildings.
I say all this to give you a sense of perspective. For thousands of years, people have looked at the pyramids and wondered how they were built.
Nothing like it had been built before or since. They were filled with indecipherable hieroglyphics, a product of an ancient and unknown culture. Their constructions have even been attributed to giants, angels, or aliens.
It's all because they were so incredibly huge, and for a long time, no one had any idea how they were built.
But with the deciphering of hieroglyphics and the advancement of archaeology as a field of study, we now have a good idea of how they were built.
The pyramids were great public monuments of a wealthy civilization with an abundance of surplus labor.
They cut blocks of stone and floated them down the river.
They organized hundreds and thousands of workers and moved the blockades.
They placed them in a pyramid shape, because it was the simplest shape the structure could take.
There is nothing technically challenging about pyramids, except organizing so many people toward a single goal.
These were built in honor of deities. But they were still built with simple tools and simple methods.
If you could somehow organize that many people again, there's nothing stopping you from building another pyramid.
And if you had the money, you could just use modern equipment to build them 100 times faster.