In the U.S. you generally check into a hotel, provide a credit card, and many guests don’t check out. It’s polite to let the hotel know you’re leaving so they can clean and turn over your room for the next guest as early as possible. However about the only selfish reason to check out usually is to make sure you get a copy of the bill.
In many parts of the world, including Asia, checking out is far more customary and can take a surprising amount of time. They’ll run your credit card again with you present and insist you sign before leaving.