Why not put power lines under ground, like other countries do? It's probably more expensive, but large scale repairs or rebuilds several times a year do not sound cheap either.
That doesn't mean it's a bad idea, and some of their network is already underground, but the reason it isn't universal is that it genuinely is very hard to do.
Yes, the cost for repair is high, but that's part of the operating budget, and each instance of repair is much cheaper than the cable-burying project, so the cost is "amortized" in a weird way that seems more palatable.
Meanwhile, the utility isn't held responsible for the economic costs related to the outage, so they don't care about those costs. Even in California, where the utility has been found liable when their infrastructure starts wildfires that kill people, they still aren't doing massive cable-burying projects.
I don't agree with it. I think it's stupid and short-sighted. But there are reasons. Most of them start with "c" and end with "apitalism".
It's not cheap. Neither is this repair cycle.
The correct way to handle above-ground powerlines is to perform regular maintenance on any trees growing near the lines. Centerpoint skimped on this expense and it resulted in 85% of Houston losing power.
I heard an interesting suggestion to double or triple every #X poles for stability so one fallen tree does not take out so many in a row.