Look to car technology. . .the original Porsche Turbo from 1974 . . lets go. . .Uh ? . . . .what happened . . .Ooops, why we left the road backwards, versus, smaller more efficient Turbos , VTG (variable turbine geometry ) & now, instant thrust when you ask for it.
An aero engine is pretty much the same, on a larger scale (or a turbo the same on a smaller scale ? ) so, lots to learn from the auto industry ( & vice versa )