> It will also take demand from existing airlines making fares lighter for everyone else.
That's not how airline economics work. The first class passengers (the ones who could afford to leave for supersonic) subsidize the economy seats[1]. If they left you would probably see worse prices, worse amenities or both.
There are airlines that don't have business or first class seats (e.g. Spirit), and they're generally a terrible experience.
On the other hand demand for premium seats would be down, lowering their price and making a nicer ride more accessible. Overall this would net to lower prices for the same distribution of amenities on a given plane ride. Supply and demand theory would seem to suggest that equal supply with lower demand leads to lower prices overall. Supply could of course adjust as more people move to supersonic, but that means more people are now getting a better product than before. And if supply of regular jets remains (they're pretty expensive to just have sit there and not try to use for income), lower-end fares and seat availability invite people at the lower end of the resource spectrum to now buy more plane tickets.
That's not how airline economics work. The first class passengers (the ones who could afford to leave for supersonic) subsidize the economy seats[1]. If they left you would probably see worse prices, worse amenities or both.
There are airlines that don't have business or first class seats (e.g. Spirit), and they're generally a terrible experience.
[1] https://www.wsj.com/articles/first-class-vs-coach-a-game-of-...