I grew up in an old (for the US), hilly east coast city and nothing was underground. Because it wasn't very dense and didn't have gridded neighborhoods, it would have been quite expensive to run utilities underground. I subsequently moved to a newer part of a different city and all the new construction had underground utilities. It still doesn't prevent outages at the substation or high voltage transfer line layers.
Power outages are a once ever few years or more thing.
For a few years I lived in a neighborhood that had above-ground lines, but further down the street they were below ground because that neighborhood was significantly richer. Our power went out fairly frequently. The neighbors told me it was because of the transition from below ground to above ground, but I also wouldn't have been surprised if NIMBYism kept older equipment in service.
That is too bad, I grew up in an desert locale that had all its power lines buried and I only experienced one power outage in fifteen years. Then I moved out to a coastal area where burying the lines wasn’t really feasible and pretty much every time it rained someone would hydroplane into a utility poll and knock out the power for a couple hours, and it rained at least once a week. If the climate permits them to bury, they should go for it.