It's not surprising that things evolve to a "best fit". Airplanes and cars are a good example. Is the reason they all look similar due to a lack of imagination,

It's not surprising that things evolve to a "best fit". Airplanes and cars are a good example. Is the reason they all look similar due to a lack of imagination, or is it due to them all converging on a form that provides the best "bang for the buck"? It is surely the latter.