Yes, copper conducts electricity better than platinum, but no on the plugs.
What vehicle and what year?
There are many other reasons, besides conductivity as to why use non-copper sparks. If OEM sparks are platinum or iridium, more often than not, they need to be replaced with the OEM plugs for optimum performance. My Axiom uses a waste spark system, so I will replace my current plugs with the OEM Denso PK16PR11 Double platinum plugs, since WSS is very sensitive to the plug type.
Platinum and iridium plugs also last 2 to 3 times longer than copper plugs, so there is less labor and expense involved into replacing spark plugs.