Most skyscrapers are assumed to have a lifespan of about 150 years. Modern maintenance and construction methods have been extending that so that older examples getting near that number are proving to have considerably longer lifespans.
But in many of the cities you’ve mentioned skyscraper tend to get replaced every 50–70 years, especially when they are non-residential skyscrapers.
Lastly, Dubai is a very young city in regards to skyscrapers, so it may be the one to follow to see how these things are addressed in the future.
MKDesign 