Shock loads break things. A hammer is a fairly simple demonstration of this. In order for things not to break, you make them out of more/stronger stuff. This increases weight, complexity cost etc. Plus, if you make things heavier, you just add force somewhere else, consider a bicycle made of hammers:
robust, but impractical.
In various types of gear transmission, there can be shock loads. A useful example is a powerful motorcycle where the rotational force from the engine may be suddenly transmitted to a stationary wheel via dumping the clutch. To avoid using a 20kg chain or snapping/bending things some motorcycles use a "cush-drive" <link>, often in the hub of the rear wheel. Here a rubber/polymer component sits between the wheel and the sprocket drive and "squishes" a bit when force is applied. This can only be short term, but it's enough to smooth out an otherwise dangerous torque pulse.
Now, imagine we use repelling S-S/N-N magnet pairs to supply a resistive force. It can also be made extremely progressive with the drive having to unstick attractive pairs and push together repelling pairs. Or "floating" in equilibrium between two sets of repelling pairs. In this configuration it should be extremely subtle/sensitive in the middle.
Rubber automotive components also degrade as anyone with car experience knows. This should be resistant to that.