Honest question here: I'm from Italy and here we have problems with fires as well. However, here power lines and district transformers are placed underground except high voltage and ultra high voltage ones, but those are above tree height and rely on much sturdier metal structures. My understanding is that burying power lines is cheaper in the long run and less prone to failures (trees falling, cars smashing the util…
From what I remember, PG&E is notorious for "procrastinating" on maintenance of its wires, as well. Wires need to be regularly checked and have nearby foliage trimmed to a safe distance. Keeping up on this maintenance would reduce the risk of fires, but California is big and the utility has decided it doesn't want to do that. So the poles are more dangerous than they should be.