Yeah, yeah, yeah; nasty noisy and otherwise un-green. But it was an amazing sight to see and even more to ride in. Paris to NYC in 2.2 hours. Curvature of the Earth out the tiny windows. Three (count 'em) three skins and reductive portholes from which to view the world.
And the nicest and most comfy ride (jeez, free slippers, free eye shades, a basket full of goodies to take home; real drinks from leveling off right through landing prep - and out of real bottles, not those little 1.2 oz shotgun shells,).
There's nothing like Mach 2 to make an Atlantic flight smooth and easy. Granted, the snaky fuselage made for never standing upright if you're over 5'7", and the portholes did get just a bit warm at full speed. Careful with your napping.
As a one time event it was wonderful (and that's not considering the first class "lounge" at Orly) and I get that it was not sustainable. Then.
And how about now? There haven't been any new technical marvels that could bring back that experience with better tech, and better fuel efficiency? Wrong. It's that nobody cares because it is not any more financially "important" than it was back then. In fact, the current business model for passenger air transport is to provide the same slow and ridiculous travel for everyone. Except if you can afford to pay 3-400 % above economy you can get the same warm moist towel, fancy drinks, reclining seats and a smiling bimbo/bimbette for twice the air time of the SST. That really doesn't make it twice as fun, trust me.
If y'all say it's not supportable due to the damage to the ozone layer, I'll say OK. And I'll just try to stay vertical long enough for sub-orbital travel that would kick the SST's ass in any case.