Most people not know that about Atlanta Hartsfield-Jackson airport but it is true. That airport is mind boggling with the passengers and cargo and everything that have to be done to make it work. People have all sorts of names for it and most I shouldn’t put on here. Cluster F**k is the one most people say when they look at all the plains waiting their turn. hahaha
Here is a list of the busiest airports in the world.
https://en.wikipedia.org/wiki/List_of_the_world's_busiest_airports_by_passenger_traffic