> The reason for that is that the concorde used afterburners (basically, pump fuel into the high speed exhaust for extra thrust) which are incredibly inefficient.

To put things in perspective, Concorde was using two Olympus engines designed originally in the 50s.

It was already a marvel that they can run for such a range at Mach 2.0 when designed 70 years ago.

A lot of things improved since. Most fighter jets can supercruise at supersonic speed without afterburners nowadays.