Underground cables have more expensive set up costs, lower lifetime, and higher maintenance costs. The price you pay for electricity doesn't even come close to justifying burying power lines. There's also the ecological stuff if you find that a reasonable argument. Bottom line, burying power cables just so you don't have to light a candle for a night isn't worth it.
Depending on where you are in the world, earthquakes are much rarer then insane storms. I'm speaking as a Floridian. I'm fairly ignorant on this issue, but would it be that difficult to use one or the other depending on which natural occurrence is more likely? Or is this also a cost issue?
"The North Carolina Utilities Commission
studied the cost of placing Duke Power’s distribution facilities underground and found it would
cost more than $41 billion, resulting in a 125 percent increase in customer rates."
Do they? Here in Germany the entire cabling within cities is underground, only the high voltage long distance lines are above ground. I've never heard a story about people stealing underground cables (they do steal e.g. train track above ground cabling). That also wouldn't make sense, digging up those cables is much more effort than taking them down from a post.
I've also never heard stories about issues with rats.
Power outages still happen, but they are quite rare - in 30 years I can only remember twoish.
I don't know but I've heard stories. Stealing cables underground is not common but it happened. And rats and underground water is quite a problem for underground (copper) cables.