Lots of ultra distance runners and cyclists eat and burn more than that. The point is with sufficient exercise it is almost impossible to stay fat.
That’s a half marathon for a 150 lbs fit person, running efficiently. A 250 lbs person who is a little out of shape will burn that in a 2.5 hour walk.
Obviously 1300 calories a day above maintenance is extreme for most people, but energy expended scales non linearly with weight. There are also a lot quicker ways to burn calories than marathon running.