For the range they're working with, it has to be glass. Plastic has way too much attenuation

It's a lot of drones on both sides

My understanding is this is essentially a hotly fought over area, or nearby a contentious area. That's why there's so many cables going through here:all the drones that were flown past this area.

That's exactly it. Every one of those lines was an FPV drone with a bomb. In addition to being impossible to jam, they also don't emit any signals so they're harder to detect.

Oh and you'll notice in some FPV videos that the video degrades as the drone gets closer to the target. This is generally due to signal interruption because of trees or terrain in the way. Fiber drones can fly as low as they damn well please with perfect video.

Riiight, I forgot about wire-guided missiles/torpedos. Makes sense to use a similar system for war drones.

Fiber-optic drones