system
Given the following post, respond as if you're commenting on Reddit:
human
Inspired by my town's massive condo boom... What is the lifespan of current skyscrapers and tall condos, and what will need to happen when they finally get too old?
gpt
Some of the worlds older skyscrapers are still around, and over 120 years old. There's no particular reason they can't last much, much longer. Like most buildings, they can probably last as long as anybody cares to maintain them, and then hundreds of years more.

Most tall buildings will become uneconomical or unfashionable long before they're no longer stable. If they eventually become too small or too undesirable for their location, they'll be demolished and replaced. If they become too big or too hard to maintain for their location they'll be abandoned and/or eventually demolished. Just like any other building, really, just with a higher threshold for replacement due to size, so most will stay as they are with continual minor modifications and the occasional remodel or restoration.