Why Has Airline Travel Slowed Down Since the 60's ?

Have modern day commercial airlines slowed down? Almost every flight today takes longer than it did in the 60's. Is it possible that we haven't progressed in 50 years?

It may have something to do with the fuel efficiency of the engines and surprisingly 'airmile' upgrades.

The Concorde was a supersonic passenger jet airliner that halved the travel time from London to New York. But compared to new era jet planes, the Concorde was no longer considered luxurious or efficient, not to mention the mechanical issues. It was therefore put to rest in 2003, thereby ending the era of commercial supersonic flight.

Via Wendover Productions