There are already multiple efforts to put supersonic planes back on the map.
Supersonic craft had two big killer problems. One was the sonic boom which made operating them over land at speed something every country made illegal very quickly, which meant you pretty much could only fly at that speed over the ocean….which severely limits potential routes.
The second is fuel economy. The simple fact is that flying slower is more economical and jet fuel is VERY expensive. Even subsonic commercial jets tend to fly slower today than they did 30 years ago because it’s more efficient. The increased competition resulting from deregulating the airlines lowered airfares for consumers…but it also decreased margins for alot of airlines.
Now, the first problem may have been solved. Aerospace engineers now believe they can made a supersonic airplane that doesn’t create a boom. This would allow future supersonic jets to fly more routes. There are also improved engine designs that might held with the second problem.
I’m not saying they’re close…but they’re working on it.