Looking at that picture I wonder how people can be so amazed by it.
That's exactly the problem. Pyramids are like the Grand Canyon. Modern photography may have gotten super good at capturing a likeness of their image, but nothing actually beats going there in person and seeing those things in real life!
Doesn't even sound hard other than the heat (which was called fucking life back then, cause no one had air conditioning).
Actually, don't believe your hollywood movies, Egypt was lush with vegetation and had plenty water (which provided its own natural air conditioning during the time those pyramids were built). Please read this article and this article.
Considering that it was made with slave labor, makes it even less impressive.
Yes, that was the totally unproven interpretation of the Europeans when they first visited Egypt. And as another poster already replied (and provided a reference), they're now finding physical evidence that this wasn't actually the case.
There's these steps in northern california, laid by like 80 japanese slave laborers like 100 years ago...
If you think the work of 80 laborers 100 years ago is equivalent to the work of ~10,000 laborers ~7,000 years ago, then that's your choice. Personally, I can't even visualize a period of 7,000 years. So if you're not impressed by several supremely huge man-made structures that have stood the test of time for 7,000+ years, then let's just agree to disagree because I am surely impressed by them.