It doesn't feel like Boom has the timing on its side either. Feels like we're still in a massive aviation crisis and I'm not sure how long it's gonna take before things look good for the industry.
(Of course they stopped supplying them in 2003 when the service was retired after the crash).
Commercial aviation tends to be a cyclical industry so there will always be a crisis somewhere on the horizon. Airlines like United are trying to broaden their offerings so that they can better maintain margins in a downturn. Some "Time is Money" expense account travelers will always have money to spend on a premium product like getting there twice as fast.
The main profit center for commercial air travel was businessmen going places, not too concerned how much flights would cost.
Now business meetings happen by video conference. Flying round the world for a 3 hour meeting will never be big again.
Now we know how to leverage video conferencing for meetings, and we are convinced more than ever of the limitations given current technology.
You're not really offering any evidence, just speculation. The actions of the major airlines suggest an expansion, not a retraction.
Concorde had a bit of bad timing. It was released during the worst crisis of aviation (until 9/11), and there was already a second version planned with increased fuel efficiency, but that came never to be with all orders being cancelled. And those cancellations also meant that all economies of scale advantages were gone.