QueSST isn't Concorde..
Whilst QueSST is providing useful research, it does seem that it has a long way to go before it enters the same league as Concorde...
Remember Concorde carried up to 128 passengers, flew from existing airports (okay they did 'longer' runways) and was able to fly transatlantic (supersonic), refuel and fly back (supersonic). Plus we shouldn't forget that the Concorde that entered service was basically the prototype, the money effectively ran out before they were able to really think about building the production version...