It depends on how much current you want. I worked on a 1.2 m major radius 1 T copper stellarator that used 10 MW of power for the confinement coils. The coils

It depends on how much current you want. I worked on a 1.2 m major radius 1 T copper stellarator that used 10 MW of power for the confinement coils. The coils are water cooled but even then the shots are only 1-second to avoid overheating (and to save on the engineering cost of the power system). Any real fusion reactor would need 5+ T confinement fields and be 2+ times the radius of this machine. You would be using many GW in ohmic losses in copper confinement coils for hundreds of MW of fusion power: it simply could never work. A cryoplant for an LTS fusion reactor would use on the order of 50 MW, a bit less for HTS. So for the big magnet application superconductors are an incredible win.