Why didn’t it succeed?
Concorde flights came to a screeching halt after only 27 years of operation on October 24, 2003. The reason? Excessive cost, high fares, and loud noise. On a regular flight, Concordes consumed 6,771 gallons of fuel, which quickly exceeded the profit made from the flight. In addition to that, only a total of 20 Concordes were built and no airline ordered them except for Air France and British Airways, who had to as they were state-run airlines at the time.
Oh, and a 2000 crash that killed everyone on board (109 people) and four people on the ground.
That’s specifically a US regulation, but costly as coast to coast across the US would be the only other viable route.
Possibly only existing as a reg because it wasn’t an American plane…