The decreased propagation time through air vs glass likely wouldn't yield latency improvement in relevant orders of magnitude. The primary benefit is cost redu

The decreased propagation time through air vs glass likely wouldn't yield latency improvement in relevant orders of magnitude. The primary benefit is cost reduction. Erecting a few towers with optical relays over high points in terrain would be cheaper overall to install & maintain than either aerial or trenched fiber. If a 3rd party builds something in your way, just relocate the tower whose line of sight becomes obscured (on the assumption tower sites are solar-powered and self-standing).