Superconductors don't have "near" perfect conductivity. They are actually perfect. They have exactly 0 resistance.

This material, even if it works as initially advertised, only supports a tiny current load, beyond which it loses superconductivity...If I understand correctly.

this article completely misrepresents what causes a transistor to create waste heat. It is not due to "current leaks". It is due to switching speed. Superconductors cannot really switch at all, at least not in anything like the sense transistors do it. Superconductors will not improve semiconductor performance any more than regular conductors would. By your logic, Why not just make a computer chip out of copper? It conducts better than silicon!