> Electrical signal attenuation increases with the square of the distance

Power transmission lines at 60Hz primarily have ohmic losses, which are linear with length of the conductor.

Interesting fact - Power transmission lines are long enough that the capacitive and inductive effects do matter a little bit, even though it's only 60Hz. That's why spacing between conductors is important. 3-phase lines will also rotate the order of conductors every so often to keep the average spacing between all pairs of lines similar.