Skyscrapers tend to start construction during an economic boom, but because they're so slow to build, by the time they're complete the boom has usually ended.
South-East Asia (Bangkok, Jakarta, KL etc) after the 1998 crisis was full of skyscrapers that were never even finished before the money ran out, the Burj Khalifa opened up just when Dubai's economy went into freefall, and Calgary is a recent example of skyscrapers being completed at exactly the wrong time:
https://news.ycombinator.com/item?id=28873926
South-East Asia (Bangkok, Jakarta, KL etc) after the 1998 crisis was full of skyscrapers that were never even finished before the money ran out, the Burj Khalifa opened up just when Dubai's economy went into freefall, and Calgary is a recent example of skyscrapers being completed at exactly the wrong time: https://news.ycombinator.com/item?id=28873926