> Whether you can fly JFK-CDG in 8 hours or 4 hours, when you factor in how irritating airports are, parking, security line ups, waiting for baggage, etc, it still takes all day to make the trip.
Security lines weren't a thing until 2001. The Concorde operated from 1976 to 2003. The retirement was due to low passenger count due to a crash in 2000 and 9/11 in 2001.