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.