Is it really such a feat though?

Mile-high tower: Saudi prince promises £5bn desert spire TWICE as tall as nearest rival being built the Daily Mail:

"Plans for a mile-high tower in the Saudi Arabian desert have been unveiled by the billionaire owner of London's Savoy Hotel.
At 5,250ft, the £5billion project, masterminded by two British engineering consultancies, will be twice as high as its nearest rivals, skyscrapers under construction in Dubai and Kuwait, and almost seven times as high as the Canary Wharf tower in London's Docklands."

We have gotten so good at building towers where is the challenge, really? I would think a more challenging aspect would be to go down .... how do you make a in-ground office/apartment building that is earthquake proof and stylish -- there are so many factors to consider.

To me THAT is a real challenge!