I’m a pilot and this is… a vast oversimplification. Jet aircraft are significantly more efficient at higher speeds and at higher altitudes precisely because there’s less drag up there and the engines can operate more efficiently. They are wildly inefficient when low and slow.
A lot of the assumptions people make about efficiency don’t hold water in aerospace. There are no laws of physics preventing supersonic aircraft from being efficient provided they can fly high enough and we figure out how to build better engines.
A lot of the assumptions people make about efficiency don’t hold water in aerospace. There are no laws of physics preventing supersonic aircraft from being efficient provided they can fly high enough and we figure out how to build better engines.