Due to high power factor, the current through the cable is reduced. Since current is inversely proportional to power factor. The cable area or diameter is reduced. This reduces unnecessary copper losses and initial constrctional cost of cable.
Also due to high pf, overloading of line is eradicated. It also increases the efficiency of transmission. It reduces the electricity bills as KVA amount is less due to high pf. It also avoids power factor penalties. These are applicable for ac circuits only.
For dc circuits, pf does not play any role in power transmission.