Not as much as is wasted in generation and transforming, both of which would benefit from superconductors. The benefit might lie less in the wires and more in

Not as much as is wasted in generation and transforming, both of which would benefit from superconductors. The benefit might lie less in the wires and more in the equipment. Tough to say with a trans Atlantic cable though. Those kinds of distances have never been tried to my knowledge.