[Sparyjerry]

Above ground power lines make up most of the it. A pole and wire isn't that expensive. Burying is drastically more expensive.

[ta1243]

So run the fibre on the power line

[Alupis]

They do, where feasible. It's still very expensive, and the poles are owned by another entity which complicates things a bit more as well.

No free lunch, as they say.