It is easy to cause postural imbalance issues with cycling through constant bending of the torso and overdevelopment of the anterior chain. Running puts the body is a more natural and balanced posture, with more involvement of the posterior chain and a rigid torso being proper running form.
Cycling lets you get somewhere faster with less effort but running is ideal for the most energy expended in the shortest amount of time (and also the least distance travelled.), more energy expended = faster muscle growth.
The fact that one may be better than the other is subjective.