People generally want to travel from areas with lots of people, to other areas with lots of people. So cities. There has actually been a proposal to move Schip

People generally want to travel from areas with lots of people, to other areas with lots of people. So cities. There has actually been a proposal to move Schiphol (Amsterdam Airport) to an artificial island in the North Sea, because Schiphol is producing a lot of noise pollution for the surrounding towns. (And not just that; my sister used to play hockey on fields under an approach, and sometimes the field would smell like kerosine.) But such a move would dramatically increase travel time to and from the city. Although maybe you could save time by having a dedicated train line and do checkin before getting in the train, passport check while on the train, etc.