> no need to tear them down after a couple of decades

Where are people constructing buildings that need to be torn down after a couple decades? This is a refrain I've heard about construction (in the US?) several times in discussions like these, and I find it very puzzling.

I believe Japan does it, for instance.

https://en.wikipedia.org/wiki/Housing_in_Japan

"An unusual feature of Japanese housing is that houses are presumed to have a limited lifespan, and are often torn down and rebuilt after a few decades,..."