It's all about perception really.
I'm generally with RickB on this.
But I would not call close to 3 million pax on Concorde 'small', unless you define it by todays mass market air travel standards, you should remember that many people flew on Concorde relatively cheaply when BA
ran extensive charters, and many of them were to destinations as well as pure pleasure flights.
In the late 80's and early 90s the now private BA
lamented that they could not get hold of more Concordes.
Another false perception, it was Conservative governments on both sides of the Channel that launched the Concorde project, not left wing ones.
As has been pointed out, 707 was a tremendous trailblazer. for Boeing, the US and air travel generally.
Would it have happened if the USAF
had not given Boeing that massive leg up in terms of the huge KC
-135 contract? (Always remember that came first, not the civil 707).
If it had not, someone else would have done it. Vickers in the UK nearly did but for an incredibly short sighted move by both BOAC (who thought in turboprop Britannia would suffice in the short term) and the then UK government, by canceling the V.1000 project.
707 had rivals, Comet 4, DC-8, the Convairs, the VC10.
Concorde had none after the 2707 was axed, and it was axed before the fuel crisis, after spending the same amount as the UK did on Concorde, it wasn't being smarter that killed the 2707, the US government was lobbied by anti SST crowd true, but the killer were the delays and redesigns.
The 707 was a tremendous aircraft, but the average joe cannot identify it over other aircraft, which you cannot say about Concorde, the SST shares that with the 747, which was more significant than both the 707 and Concorde.