I think the cost of labor and materials and sheer amount of construction work needed, are what prevents us from putting more electrical lines underground.
There have been efforts in San Diego to put power lines underground. In newly developed areas, they are routinely put underground, as new areas are developed. In established urban or suburban areas, only a handful have had their lines buried.
I heard cost estimates of tens of billions of dollars, and a time line of decades, in order to get all the power lines in San Diego underground. When you get into the billions of dollars, you are talking serious money, and the efforts to put power lines underground competes with other spending priorities.
Is there enough money, and especially manpower; do we have enough trained men to do that actual work, to get it done?? That’s the question.