Throughout history, as the speed of transport increased, a greater portion of the public could afford the TIME to travel more widely. From sailing ship to steam, horse-drawn to rail, 80 mph to 150 to 300 to m0.8, each time the market mushroomed.
So why wasn't a m2.0 plane a runaway success? It certainly wasn't for lack of glamour.
It just wasn't ENOUGH of a time-saver. Speed from takeoff to touchdown was wonderful, but that wasn't sufficient; From Manhattan to Montmartre still required surface transport, baggage check & claim, airport surface congestion, and other queues that seriously diluted the speed advantage of the Concorde.
The whole transportation SYSTEM must be addressed for any new SST to succeed.