My completely uninformed guess is that light can be incredibly information dense, but not all that energy dense compared to electricity. Also fiber is a little

My completely uninformed guess is that light can be incredibly information dense, but not all that energy dense compared to electricity. Also fiber is a little more brittle and persnickety than electrical wire, so in this specific use case it would seem to be strictly worse, at least when it comes to the immediate challenge of cables experiencing physical harm.