What I try to get across is that this is not some army backpack and paraphernalia.
We're talking going in extreme heat (Egypt!), with sandals on your feet, and with 20+ people coordinating to pull a 2.5 ton rock (with some larger rocks going up to 6 tons). And then somehow pull it up, up to 400+ feet.
And even for the army, most of them having to carry 200 pounds for any extended period will end up royally fucked up after a few hours of this, much less entire years of working on such projects for hours every day...
Actually, do you know that for certain? These were decades long efforts, at least, so some specialized harnesses and paraphernalia probably were invented along the way.
For a direct comparison you can look at how many people moved litters over long distances. There are a few natural poisons to carry a litter especially if you can group people by height. https://en.m.wikipedia.org/wiki/Litter_(vehicle) People would get swapped in an out for long trips allowing for faster speeds, but up to ~100lb per person via logs was not uncommon.
They are also expected to be able to move someone else with most of that gear attached to the both of them.
Really, carrying 50 pounds most of the day or lifting 200 pounds off the ground and moving to is reasonable for most physically fit people.