You still can fly from some of the regions to LGW and connect to VN, it keeps the money and jobs in the UK.
Pretty soon I wont be able to fly there from my local airport, and a short hop to LGW to conenct with a foreign carrier is hardly going to contribute massively to the UK economy. And to counter the argument foreign carriers flying to airports outside the South East are bringing money into those economies that would otherwise be funnelled to the one region that needs it the least. The economic benefit argument works both ways.