But the reason for the expense is largely the weight.

Yes we can at great expense support massive weights. But even in skyscrapers, you aren’t expecting to just cram every floor with equipment that weighs over a ton and supported by less than a square meter of floor.

It’s not just armchair engineering, i work in the industry and commonly you have racks preferring the ground floor and weight restrictions going up and even marked paths that the racks need to stay on when on upper floors due to limitations of the reinforcements.

Skyscrapers are largely impractical structures done for the sake of showing off, with any value based on keeping people close to each other. No one builds a skyscraper by itself miles from anything else. This is where they build the datacenters because they don’t need proximity.