One of the benefits of my new job is that I get to talk to people who have been working in aviation since before I was born.
They said that Concorde was likely the last airplane of its type. It was a dream that they decided to design and build and justify later.
It's all business now, and if you can't cost justify something, it gets killed. For example, back in the day, the Sonic Cruiser would have been built and the execs at Boeing and the airlines would have found a way to justify it later. One exec they talked to said the aviation buff in him wants the Sonic Cruiser, but the businessman can't justify it.
It's really sad, in my view. Aviation to me has always represented man's quest to soar and now it's all dollars and cents. Or in the case of Concorde, all pounds and pence.