JFK-LHR is still one billion dollars in revenue for British Airways alone.
The innovation that killed Concorde was the lie flat business seat. You could be cramped in the Concorde’s leather bus seat for three hours, or you could save money and get a sleep in for six hours.
Not really, because Concorde died in the seventies when the lie flat business seat didn't exist.
BA and AF managed to keep the zombie fleet going very profitably all the way until the end in the early 2000s, and that business wasn't killed by the lie flat business class seat either. It was killed by the impossibility of continuing to operate a tiny fleet of '60s planes forever.
Now if you said that the reason we don't have ANY supersonic passenger jets today is because lie flat business seats are good enough, then that's a more defendable position, but I'd still say that the overland flight restrictions limiting any SST to just a couple of routes is a bigger factor.
When I flew on Concorde the one thought I never had was "I wish I had a lie flat seat and half the airspeed".
It is the combination of lie flat seat and the very limited range and the overland restriction.
A six to three hour flight is not really worth the premium. At the same time no supersonic flight has the range to do transpacific where the time difference would be much greater.
It's still a huge route but it's also something you can do on a day flight. Heck, from Boston, I can fly to EWR and still be in London for a late dinner. I don't even need a lie-flat seat.
The extra $4K or so in your pocket pays for a lot of reduced comfort for 10 or so hours.
The innovation that killed Concorde was the lie flat business seat. You could be cramped in the Concorde’s leather bus seat for three hours, or you could save money and get a sleep in for six hours.