Thanks. We had no overhead wires in the Chicago suburbs, nor do we here in SW Fort Wayne.
Density is part of it, but also in dense cities "concrete jungles" the close spacing of buildings, high rises and other obstacles make putting up poles and areal wires impractical. Else they would look like cities in other poorer countries.And, the density of customers will support that expense.
They do it in some towns near me. And they pay $$ for it.