the higher you go the more load is born by the base---thus why the pyramids work in their form, but to build a hollow cube of the same size with rock---u gonna need a bit more ingenuity and math and pillars and crossbars. and the pyramids we see are the big, well-constructed ones---the first attempts, only small zigurrats truly, are mostly lost to the sands, and then you got other wonky attempts that look more like stone turnips than anything else. what you see on the postcards are the apotheosis of centuries of architectural experimentation. they had the labor, they did it.
today the higher you go the more you gonna wanna factor in things like seismic activity and wind. the steel has to have a certain tensile strength etc. etc. then add a plethora of other utilities that are needed before the building is considered 'safe and habitable' by the local council or whatever, depending on building type and location: plumbing, elevators, wiring, gas, walls, doors and windows---the amount of specialist labor needed for all these amenities is surely more complex than that of the pyramids, which basically had the following production line: quarry>boat> site>ramps.
now we ain't even talkin' bout tiling, swimming pools, furnishing, and a plethora of other such---all of this has to be calculated and approxiamated beforehand by the architects and engineers to make a stable structure depending on local laws.