That really only works to a point, because it's still expensive to make the necessary glass fibre cable - and sending HV through the HV cables loses around four times the EU compared to upstepping to EV and sending it all along HV cable (Glass fibre cannot send EV). If you need to make more than, say, eight Glass fibre cables (total length 53 with your example), then it's better to step up the voltage.
Good point totally forgot you can't send EV through glass fibre.