What if the Egyptians had decided to build the pyramids higher?

It could be built to the height of a high mountain if resources were not an issue, which is probably in the region of 5 or so miles. After that it becomes an issue of geology versus gravity, with the increasing weight making it sink into the ground.

On the practicality front, the issue is that going higher and higher is a cubic law.

So for instance, to increase by 150m when doubling from 150m to 300m increases the volume by

2^3 - 1^3 = 7

ie it needs an additional 7 times the material

But increasing by 150m to go from 9 times the height to 10 times the height increases the volume by

10^3 - 9^3 = 271

ie the increase in height of 150m from 9 to 10 times requires 271 times the whole original volume,

and the whole thing would be 1,000 times the volume of material.

ALSO remember, that the BASE also increases in area with height thus spreading the load over a wider area.-----its not just a matter of stacking rock blocks on top of another until the weight equals the 'crushing weight. ALSO the pyramids were not made of simple layers of stepped rocks, but rather many of the rocks were laid at sloping angles in a "Core area", to direct the compressive forces downwards at spreading angles from the center. The "steps" were only on the outside of the core to hold the edges of the "casing stones.----So the structures of these things were not as straightforward as we might think. And they WERE big---Almost a 50 story building with nothing else to compare with it, they likely thought it was big enough.

At some point, they would exceed the capacity of something. I think the underlying earth would be ok for quite an immense load - the Giza pyramids were build on a granite plateau, lots of bearing capacity. It is likely that the limit for height and weight would be determined by how much weight it would take to crush the stones on the lower levels.

It would depend on the earth under the pyramid and the compressive strength of the rock being used for the pyramid. The soil under the base has to be strong enough to support the weight and the rock that makes up the low layers of the pyramid has to be strong enough to not be crushed by the weight of the rocks above.

FORGET IT, EGYPT GOVERNMENT RATHER SPENDS MORE MONEY ON MILITARY FORCE TO ENFORCE ITS NO ENDING WAR AMONG ARAB COUNTRIES.

The structure is strong, I think the first failure point would be the whole thing sinking into the ground. But I don't know how much weight that would take, depends on the geology of that area.

Depending on what level of reality you want, there's probably a point where there's enough stone to continue building but it's lower quality and can't support a large structure.

Assuming labor and material are not a problem is, of course, absurdly unrealistic.