Airports were once visitor attractions. Most people did not go there to fly, they went to look, wonder and eat at these exotic modernist enclaves. In 1939, New York’s La Guardia attracted 250,000 visitors a month, when the number of actual passengers was only 3,000 a day. Berlin had a 3,000-seat restaurant on the roof. Flying was a secondary function of the airport.

Never such innocence again. Nobody now goes to an airport for fun. Consider Heathrow Terminal Three, where every day is a busy day. Along with megahubs like Atlanta and Shanghai, Heathrow ‘handles’ – le mot juste – more than 50 million passengers a year.

The vast majority are flying what Americans euphemistically call ‘coach’, which means seats designed for double amputees and whose appetite can be sated by a ‘snack’. These desperate folk, having queued, been scanned and made their way through the luxury goods and giant Toblerone shops, settle into Three’s seething mass of anxiety and irritation, where everybody sits and waits for their gate to appear on the screen.

Until then, they are trapped. They are not – and here is the key word – ‘special’. Being special usually involves money – flying business gets you a special lounge, flying first gets you an even more special lounge and, if you want to be supremely special, you can book yourself into Heathrow’s Windsor Suite, which costs £3,000 upwards per person.

Airports, in short, have become a class joke: fancy architecture deployed ruthlessly to enforce social inequality. This moment of becoming can be accurately dated to 1977. That was when ITV aired an ad for Campari. Actor Jeremy Clyde leans in to murmur into the ear of Cockney beauty Lorraine Chase, ‘Were you truly wafted here from paradise?’ The literalist lovely replies, ‘Naah, Luton Airport!’

Luton Airport had become a joke. It still is, an incomprehensibly designed system for shovelling five and a half million people a year in and out of its quasi-modernist sheds, or, to put it another way, to take the strain off Heathrow. Without Luton and other mini-hubs, fed by the new low-cost airlines specialising in familiar holiday destinations, Terminal Three would have descended into civil war or mass suicide.

This is not entirely an exaggeration. Recently I was leaving Heathrow for Amsterdam’s Schiphol when a row broke out ahead of me in the passport-checking queue. The checker was patiently explaining to a young couple that they could not board because their passports were out of date. The girl was furious, not, as I first assumed, with her boyfriend, but with the official. Blind and utterly irrational anger is never far from the surface in a crowded airport.

Schiphol, meanwhile, is built on a lie. Flying time from Heathrow is said to be one hour, in fact it’s forty minutes. When you land the problem becomes obvious: there are no buildings in sight. It takes twenty minutues to reach the terminal, which is a gigantic shopping centre. But, in Norfolk where I live much of the time, it is paradise. You could go to Norwich’s tiny airport, fly to Schiphol and connect to wherever the hell you like – much better than driving three hours plus to Heathrow and expiring with insensate rage in Terminal Three.

But what is the big picture here? Well there are now more than 100 airports worldwide handling over 10 million passengers annually. Five of the top ten are in America: Atlanta, Dallas-Fort Worth, Denver, Chicago and Los Angeles. This makes sense because fifty per cent of the world’s take-offs and landing happen in the US, so international hubs are not so busy.  The other megahubs are Dubai, Istanbul, France, London and Delhi. Shanghai and Beijing are catching up and the Saudis, typically, have built the biggest airport in terms of size – the 776 square kilometre King Fahd International.

Now, assuming airline traffic continues to grow at its present rate and aircraft technology remains roughly the same, even the newest of these will look like Heathrow in ten or twenty years – a random collection of glumly functional buildings punctured by the occasional show-offy architecture prize-winning shed.

The essential shape of the airport was determined after the Second World War, when the design of passenger craft settled on the heavy monoplane. Before the war, take-off and landings strips had measured around 2,000 feet and seaplanes had handled long distances. Now runways can be anything up to 16,000-feet long – the length of the Shigatse Peace Airport runway in China.

Personally, I mourn the passing of the short or awkwardly engineered runway. Flying into the old Kai Tak airport in Hong Kong used to be one of the last great thrills of air travel. Pilots had to be specially trained to fly 747s in between the tower blocks and passengers would be thrilled by seeing what the locals were cooking for supper that night. That is gone but the perilously short Gibraltar runway remains. Preventing an Airbus A340 from plunging into the Mediterranean requires very hard braking. This, happily, can still be experienced and the passengers applaud every time in gratitude for being undrowned.

I mourn something else: the passing of the 747 Jumbo jet, one of the most beautiful machines of the modern world and now replaced in the jumbo format only by the hideous Airbus A380, the front end of which looks like a hydrocephalic child.

On a brighter note, I don’t think technology will continue to demand the industrialised forms of airports. Passenger planes all look the same to me and they all look antique. Also, see above, airports are no longer visitor attractions.  Maybe space or vertical take-off machines will arrive; maybe AI will makes it possible to experience Ibiza or Barbados in the comfort of your living space.

But, for the moment, I think all business, first class and Windsor lounges should be encased in glass. Watching the luxuries inside will provide the masses with entertainment and redirect their rage outwards. It could also guilt-trip the airlines out of their miserable little seats and patronising snacks.