We don't have a reliable age for the Great Pyramid. Since we can't do radiocarbon dating on rocks, all of the estimates are based on somewhat circumstantial evidence. It could be much older, possibly with some more recent maintenance. I'm not claiming any particular age, just that we don't really know.

While we can't radiocarbon date rocks, we can do that with other building material. From Wikipedia:

Mortar was used generously in the Great Pyramid's construction. In the mixing process ashes from fires were added to the mortar, organic material that could be extracted and radiocarbon dated. A total of 46 samples of the mortar were taken in 1984 and 1995, making sure they were clearly inherent to the original structure and could not have been incorporated at a later date. The results were calibrated to 2871–2604 BC.

Compelling evidence, but if the aliens who built the pyramids brought in mortar from another planet, the isotopic ratios could be totally different. So the date of the pyramids could be anything really if we throw out Occam’s razor and rationality in general.

could you please highlight where you think the poster threw out Occam's razor? Probing the mortar seems to be to be a reasonable proxy for the age of the construction?

I read that comment as a sarcastic response to the "we don't know the Great Pyramid's age" claim, rather than a disagreement with my mortar post.

ah that makes more sense!

There's plenty of evidence that it was built for the Pharoah Khufu about 4,500 years ago.

To suggest otherwise is just insane aliens conspiracy theory nonsense. Is this post a satire of that BS? I really find it hard to tell.