Underground electric distribution is considerably more reliable than overhead lines. Animals digging up the wire is much more rare than an outage created by an animal crawling up a pole and grabbing the line/transformer.
Underground electric is quite widely used in the Midwest and is cost effective vs. overhead lines even in sparsely populated rural areas.
Below-ground power distribution is cheaper in sparsely-populated rural areas than overhead lines because utility companies can trench the lines directly through anyone's field or in any random ditch - there's no directional boring required (until customer delivery possibly.)
Add in the fact that you no longer risk trees taking down lines when they are unkempt and ice-covered and it is probably much cheaper.
Underground electric is quite widely used in the Midwest and is cost effective vs. overhead lines even in sparsely populated rural areas.