I would venture the key reason why we do not have the 'fine grain' of different travel destinations and combinations is policing it. Trying to identify that a person arriving from a European country at, say LTN might take a train to Birmingham or drive to Manchester? The current situation is beyond accurate monitoring. Whilst I live in Hertfordshire, I have had to use Gatwick severa times due to destination and availability.
I agree that the Press are hounding the govt and, as they are wedded to the Press, they try to please them. Yet, as I have said before, this is a circumstance that no one had prepared for and everyone is making it up as they go along. We will not know who did best for at least another year and it could be three years before all analysis is complete.
Referencing an earlier point in the thread: LHR Third Runway will never be built.