Indeed, i think the word plasmahal is looking for is that it proved that it was possible rather than very feasible.adjective: feasible
possible to do easily or conveniently.
Using the definition of the word, I don't think you can describe the operation of Concorde aircraft as that.
I think the same applies today to be honest. Yes there have been massive advances in aviation technology, but these advances do not mean that the gulf between subsonic and supersonic is any narrower than it ever was. We also have the environmental lobby these days. I cant see supersonic ever being feasible in any currently recognisable form tbh.