The problem with SS commercial aircraft has always been utterly shameful fuel burn. Programs like Concorde never turned a profit, and spent the final years in the red. Booms and decibels led to flight restrictions, which had the effect of increasing burn as well. Prices ended up rising on the tickets, and that led to a niche exclusivity rather than widespread airline transport.

If someone could find a way to make a fuel efficient SS airliner, it could be a game changer. But it's precarious, because it's been decades since speed was the primary factor in airline innovation. The last 20 years have seen capacity take it's place. The more butts in seats, the better. I would even go so far as to say that planes have gotten slower since the 80's. Fewer clean wing aircraft with 3 engines mounted at the back..speed restrictions to spare fuel..fewer powerful heavies on transcons.

It may be possible to bring down consumption from Concorde levels using lighter materials, carbon fiber, efficient engines etc..but would it compete with the new next gen fuel sipping aircraft?