I was responding to the idea that disruption would occur by means of drones and 3D printing. (I agree that for small amounts of materials, this might someday be the case, but currently, this is obviously not a "ripe," disruptive alternative.) You simply cannot beat the efficiency of this mode of transport for large amounts of material.
If you want to disrupt this industry, a completely different mode of transport would have to be invented. Good luck building your teleporters or your ocean-length, frictionless rail lines, everyone!
