Nice try tears but the real world isnt about £100 boiled eggs and ego and vanity if you like come into it.
London is a worl d city no one would argue with that . It does however have very poor infrastructure in most respects compared with its competing cities in Europe. Paris Frankfurt Amsterdam all of whom have vastly more runway capacity. Like it or not London does need to compete with those places and having an airport that goes into meltdown because of an hour of fog isnt acceptable to the ever traveling global business comunity.
Also our self harm Brexit vote means that at least in theory we need more runway capacity to allow more destinations to be served on Long haul . Long haul flying needs hub type operations because witha few exceptions a fair proportion of passengers are going to transit the primary destination-thats just the way airlines work. So to meet that demand you need to expand at LHR because Gatwick is and never will be a hub , it is however ideal for the Easy Jets of the world
So because of competition and changing trade patterns we do, in the normal sense of the word, need a third runway at LHR.
The ludicrous rip off price is something else but thats just the Uk where private contractors rob the government and public services and therefore us at every turn