Work Step by Step
The "high voltage" that we refer to in power transmission is the voltage between the wire and the electric potential of the ground, not from one end of the wire to the other end of the same wire. The high voltage difference between the wire and ground, multiplied by the current, yields the high power delivered to the load. However, the voltage difference between the wire's ends is relatively small, because of the small current in the wire. That small voltage difference, multiplied by the current, gives the (much smaller) power that is dissipated in the wire. In summary, the high voltage and low current refer to different parts of the overall circuit. There is no contradiction.