Asklemmy

Fiber can deliver a single 800gigabit connection over a single strand of fiber, and if you have multiple connections you want to run over a single fiber you can use different colors for each connection and run theoretically up to 2048 different connections over a single strand of fiber. (Currently most commercial deployments top out at about 160 connections per fiber strand)

Since these various connections are all made up of specific wavelengths of light, they can be "switched" by simply running the light through a prism, meaning a ton of your network infrastructure is entirely passive and doesn't require any electricity to operate, reducing downtime, complexity and cost

One downside of fiber is you generally need one connection for uplink and one for downlink, but there are bidi transceivers which either use 2 wavelengths, one for uplink and one for down, or will time share uplink and downlink. Or since each of these individual strands of fiber are incredibly small, literally about 7 microns across, you can pack hundred or even thousands of strands of fiber into one cable.

Fiber also operates at literally the speed of light, meaning the connection to the Internet is incredibly low latency. Fiber also doesn't rust like coax or telephone wires. As long as the actual fiber isn't broken you can keep replacing the transceivers at each end indefinitely to upgrade the connection

I will agree though, it is super cool that multi-gig connections ultimately are possible over existing coax networks. I didn't think I'd see it but here we are!

Edit: I was a little out of date. Currently up to 1.6Terrabit over fiber