“Slightly confused here.... aren’t insulators used to separate conductors? What good is a material that conducts, as an insulator?”
Think of a switch. When off, the air insulates the lightbulb from the voltage.
When on, it conducts.
Now think of semi-conductors. Normally insulates but with an applied voltage, become ‘switch on’.
Now think of a ‘wire’ that is an insulator that when pressure is applied becomes ‘switched on’.
Only now that ‘wire’ is a superconducting wire!
Insulators are used to physically separate conductors. At what point do you want your insulator to become a conductor, and short out all that it protects?
Still confused!