For most of my trips, a huge % of the travel time is outside the actual flight time. Trip to the airport, security, boarding, waiting to take off, and reverse on the other side (with addition of potentially getting a rental car). This can be solved without supersonic solutions (e.g. flying private), but adoption is low for business travel – is it too expensive?

Separately, I wonder if a lot of the demand is also obviated by in-air wifi.