I think supersonic flight will never become the norm. Boom Overture would, if Boom succeeds, be more fuel efficient than the Concorde but definitely not more fuel efficient than a modern subsonic airliner. And subsonic jets are 'fast enough' for most people who don't have cash burning a hole in their pocket.
It really depends on the price, if it's 2 x subsonic-econ then I think they have a real winner (I would personally pay that, its like doing premium economy), but if its 5x or 10x maybe not
