Others have mentioned the efficiency of cooling individual rooms instead of the entire home so I'll skip that. (Not to mention that in Korea and Japan, halls are considered "outdoors" and are not heated or cooled, which is a massive waste of energy for the few seconds that people spend in the hallways.)

My issue is that any place I've lived with central AC (or a condo with a fan coil unit) is that when it's actually hot, the central units don't have enough capacity to cool my unit down enough and don't provide enough control. It's like the old cable modem congestion problem where the whole neighbourhood slows down during peak times.

Heat is even worse; when buildings are heated centrally they're usually much too warm in the winter and I end up with my balcony door opened to let the heat escape. Vastly less efficient than letting me heat my own unit.

By forcing people to heat and cool only their units as required, people either get the exact temperature they want, or will accept a non-ideal temperature and supplement with fans to save money.