I think you're confusing "Egyptian economic activity related to tourism" with "the existence of civilization in Egypt".
I think you're confusing "Egyptian economic activity related to tourism" with "the existence of civilization in Egypt".
Djoser's pyramid seems to have been completed around a hundred years prior to that, and would have drawn crowds sufficient to warrant the large temple, grand entrance, and colonnades which are part of the complex.
There is a great deal of evidence that offerings provided by people traveling to these complexes sustained the religious orders on site who provided guardianship, maintenance, and worship. And that this was planned as part of the construction.
Today tourism makes up a little more than 10% of the economy of Egypt. 2500 years ago, it would have been around 0%, for the simple reason that almost nobody could afford to be a tourist. The big businesses were grain and gold. 5000 years ago, it was actually 0%. That's when the desertification of the Sahara began and the people who had lived there came to Egypt and inserted themselves at the top of society.
It's very interesting to imagine the "green Sahara" cultures, with all of their cities and temples now under tons of sand, that we otherwise have no knowledge of.
Praying wasn't even free, if they had to sacrifice some animal.