The Chinese have a solution to that, The Boat-Car-Plane, an amphibious flying car:The problem with that is that the system may have been developed for a specific situation. Example. Sword fighting systems lack a good set of punching and kicking techniques. Is it incomplete?
Is a car incomplete because it cannot drive on water? Is boxing incomplete because it has no kicking? There won't be a one size fits all for martial arts.
Looks cool, but it cannot function as well on land as a good car, on water as well as a good boat, or in the air as well as a good plane. You can't do everything and do it all really well. The same applies to MA.