Furthermore, various structures securely dated to the Old Kingdom show only erosion that was caused by wind and sand (very distinct from the water erosion).

So where’s their water erosion then?

Just to save the downvoters some trouble, I’m only suggesting that theories which are not supported by direct anthropological evidence are worth considering. I’m not saying aliens - or Atlanteans or whomever - carved the Sphinx. The erosion theory was just the first thing I thought of as an example.

Back in the early 1990s, when I first suggested that the Great Sphinx was much older than generally believed at the time, I was challenged by Egyptologists who asked, "Where is the evidence of that earlier civilization?" that could have built the Sphinx.

They were sure that sophisticated culture, what we call civilization, did not exist prior to about 3000 or 4000 BCE. Now, however, there is evidence of high culture dating back to approximately 12,000 years ago, at a site in Turkey known as Göbekli Tepe. A major mystery has been why these early glimmerings of civilization and high culture disappeared, only to reemerge thousands of years later.

https://www.robertschoch.com/sphinx.html

The Sphinx water erosion hypothesis is a fringe claim, contending that the Great Sphinx of Giza and its enclosing walls eroded primarily due to ancient floods or rainfalls, attributing their creation to Plato's lost civilization of Atlantis

(Italics added, because - what? I’ve never seen that)

Here’s another example of this type of argument from the larger article:

The Orion correlation theory posits that it was instead aligned to face the constellation of Leo during the vernal equinox around 10,500 BC. The idea is considered pseudoarchaeology by academia, because no textual or archaeological evidence supports this to be the reason for the orientation of the Sphinx

(Italics added) Whether it is or is not; the countervailing argument is “no, because we have no proof it is”. Well no proof is just that - no proof either way. Isn’t it? This theory of astronomical alignment is based on solid empirical facts, though it is just a theory. Saying, “no it can’t be because we haven’t found a book from the time period” is a weird argument to say it disproves it. At best it says it can’t prove it.

That’s not to say a core sample test isn’t a good indicator, or some of the other causes-for-erosion aren’t as-or-more likely in the case of dating the Sphinx structure. It’s just that the particular argument that “we haven’t dug up definitive proof” is - not a great argument to base an unchallengeable assertion on. At best one has to allow alternate theories which have not been empirically disproven are possible.