But when that fancy duck wants to get to Paris in a hurry, it still has to hop on a fixed-wing Concorde like everyone else.
GNU Terry Pratchett
https://en.wikipedia.org/wiki/Bombardier_beetle
(on a much smaller scale)
Once you have technology that enables flapping type motion, it's opening up the applicable physics to like 6 degrees of freedom versus zero in current wing technology (fixed = 0 degree of freedom); much more complex and interesting to study.
How else will we move toward ornithopter style wings, or vehicles that can hover via wing movement.
I guess “supersonic wing flapping” would have similar problems, but maybe there are more clever solutions than can be modeled, with so much degree of freedom?
And is “supersonic flapping” even possible?