Anyone been on a real short flight.

CO at one time operated even 737's from IAH-HOU.

Many years back EA and DL would operated from FLL to MIA usually for
either market consolidation or aircraft positioning.

At one time I lived in FLL. Was going to NAS one weekend. Took a morning
flight FLL-MIA changed planes in MIA for NAS.

I flew CO FLL-PBI-CLE

I think AA used to do a IAD-DCA that continued on to DFW

I do not think I have ever seen scheduled flights JFK-LGA-EWR or any
combination, only ferry flights.