the steel core made it possible to made full glass facades, but it didn't make it necessary
it was even more so of a conscious decision not to use any ornamentation that they weren't limited to stone facades (btw many steel core buildings had stone facades until recently, among other materials like precast concrete - in the financial district of London most buildings pre 2010 are not glass, and most post 2010 are)
it just seems to be the case that the ruling elites like those buildings, and that's the main reason they are pervasive across skylines
it was even more so of a conscious decision not to use any ornamentation that they weren't limited to stone facades (btw many steel core buildings had stone facades until recently, among other materials like precast concrete - in the financial district of London most buildings pre 2010 are not glass, and most post 2010 are)
it just seems to be the case that the ruling elites like those buildings, and that's the main reason they are pervasive across skylines