The fiber is also used for TV etc., with several providers on the same fiber, so I imagine that the fiber provider gets income from the competing TV providers as well. Could be part of the why. As for myself, I only need and only pay for actual internet.
I've had 1Gb/1Gb fiber for many years now, and lately fiber arrives in the most unexpected areas (long distances, few residents). It (the deployment, not the monthly) used to be more costly, but it's not anymore. And no public money involved. I know that it used to be, as an experiment, a couple of decades or more ago, but only in certain areas.
Sometimes this can even be a problem in cities when the available infrastructure is at the limit. It's quite possible to move to an area, after having checked that good internet is available and suddenly the provider says no when signing up.