New York flights
The runway at Leeds needs to be extended by a couple of hundred metres or so (at the Leeds end) to allow the 757s to take off at higher weights and still clear Otley Chevin. Once that is done, flights to NewYork could work.
When Jet2 did those four trips to NewYork last year, two of them had to make a tech stop for fuel. This adds cost to the trip. No airline will want to run the route when a large percentage of the trips will have to do extra tech stops.