Nowadays, plane journeys are actually longer than they were 20 years ago due to economical reasons (‘as always!’ we hear you say). This specifically comes down to fuel, as expert Mark Drela explains:
Going faster eats more fuel per passenger-mile. This is especially true with the newer high-bypass’ jet engines with their large-diameter front fans.
Lowering the speed to save money
To put it simply, the more passengers there are on a flight and the faster the plane flies, the more fuel it consumes and as a result, the more expensive it is to run. So, in order to save money and reduce ticket prices, airlines decided to reduce their cruising speed.
Moreover, although the speed of commercial flights in 1960 was 525 knots, nowadays, these same planes operate at a speed of between 480 and 510 knots.
According to Business Insider, this new system works really well. A press release from 2008 revealed that, in one year, the American airline company Jetblue saved the equivalent of more than £9.5 million. A huge saving for just a few more minutes on each flight.