The pyramids of Gizeh are one of the Seven Wonders of the Ancient World - and the only one that does still exist today.

There have been long discussions about how these pyramids could have been built - and while there are plausbile theories, there is no finite conclusion. But what we do know is, with our current building technology we would not easily be able to build such a thing; neither technically nor organizationally nor economically.

So, given that in our current culture we would probably fail when trying to build such a monumental thing, how then could the ancients succeed? This is hard to believe, and a couple of alternative theories came up, one of them being that aliens, i.e. extraterrestrials might have guided the build.

This is again difficult to believe, specifically if one doesn't believe in aliens. Furthermore, it was shown that these theories are not really well-researched and appear to be selective on those facts that would fit into the theory. Therefore not much attention was given to these theories in the scientific community.

But also, there is an essential difference between science and ideology. Ideology promotes a truth, and that truth is defined by the ideology alone.
Science on the contrary does not have a truth, science does only have theories, and these theories are more or less likely, depending on how well founded they are and how precise they match the observable facts. So while it is extremely unlikely and probably not worth investigating whether aliens built the pyramids, it is still not absolutely guaranteed that they didn't. Because that is how science works: it does not provide us with absolute truth.

However, in recent years a great new breakthrough of science happened, which extremely simplifies research and answers most of our open questions. It was found that all the scientific theories that you do not like or consider as implausible, are created by racists.
So now if you look up the alternative theories about the pyramids having been built by aliens, you find lots of sources - but if you would like to know why these theories are bogus, why they are ill-researched and unsubstantial, you do not find any argument, except that they are racist - and this is now the absolute truth that science can provide! So you don't need to know the arguments anymore, because racists is all you need to know.

In fact this simplifies the scientific business to an enormous degree: since we are now able to discern between viable and non-viable theories by declaring the non-vialble ones racist, and thereby obtain an absolute truth, there are no other arguments needed anymore. Discussion can now be abandoned entirely, and only obedience and belief is required and expected by the scientific community.