But the smaller planes are more efficient and scale better.
It's a tragedy-of-the-commons situation, like traffic congestion on a roadway.
There's another factor: these big-ass planes of A380 and alike produce a lot of wake turbulence - in fact, the A380 so much that it has its own strength category and its wake turbulences nearly shot another plane out of the sky (http://avherald.com/h?article=4a5e80f3). This means that an airport may dispatch more lighter planes in the same time than heavier planes.
It's easy to build a new runway, or a new airport, in the desert, or when you can evict anyone in the way. But try doing in a country ruled by law, when the city has long engulfed the airport build in the 60s.
However, that's still only <10 airports in a world of thousands. Pretty much every major Asian airport (with the exception of Haneda) has tons of room to expand, and most are already doing so. Congestion is hardly an issue there. Even in the US, there are still airports with plenty of unused capacity: DFW, Denver, Dulles, Phoenix, Minneapolis, Detroit, etc have plenty of room to build new terminals and runways as needed. Even LAX and ATL are still sitting on plenty of land awaiting terminal expansion. And the same can be said for much of the small-medium sized airports in the US as well.
The A380 is important to JFK and LHR slots, but I think it's much more likely that we see a the growth of alternate airports and more point-to-point travel than it is that the entire industry will make an about-face regarding the A380 just for the sake of a handful of airports.
The airport already has six runways and the master plan calls for six more. Two of the three existing concourses can be lengthened to add more gates and the plan allows for four more concourses without needing to reconfigure runways. Last year the city approved a plan for 39 new gates.
(In case you've ever wondered why taxiing at DEN takes forever, this is why)
1: https://airwaysmag.com/wp-content/uploads/2016/10/noahjeppso...
And traffic growth to those destinations is huge.
Also don’t forget that airspace is also quite congested.
> Also don’t forget that airspace is also quite congested.
Airspace is congested around specific airports, but the same situation applies: there are other airports with almost zero airspace congestion that can easily pick up the slack. If you're talking about jetstreams, we're almost nowhere near saturating the available airspace over the Atlantic.
1: https://www.panynj.gov/airports/pdf-traffic/ATR2016.pdf
2: https://www.statista.com/statistics/303920/flight-transfers-...
So when total traffic doubles, that’ll be a 160% increase to JFK even if you remove all the “hub” traffic, which is unlikely, and you assume the increase will be evenly distributed, also unlikely.
UPDATE: I don't see how the "direct to smaller airports" is anything but a temporary reprieve that will be overwhelmed by the overall trends: concentration of population in ever larger cities and increasing travel.
> New York, London, Tokyo etc. are not random places in the boonies that serve as hubs, they are destinations.
This is much different than your second comment stating the "majority" of traffic. Hell, your second comment even contradicts your first comment: in the first, you claim they are not hubs, and in the second, you acknowledge that they are hubs.
Empirically, your first statement is not true, and now you're trying to move the goalposts. As my numbers show, over a fifth of passenger traffic (which is a very significant number) to those airports are connecting passengers, and use those airports as a hub. Therefor, your claim that these airports are not hubs is false.
Between 30 and 40% of passengers departing from JFK or Newark will go on to a connection [1]. Switching to point-to-point travel means reducing traffic at these hubs.
[1] https://www.panynj.gov/airports/pdf-traffic/ATR_2015.pdf