In Europe, even rural areas tend to be fairly close to cities, whereas in North America, lots of farms are really remote. This map from NASA [0] should give you an idea of how remote some areas can be.

Now, 99% of these areas have electricity from the grid and analogue phone lines, so there's no reason why we couldn't also run fibre out to them, but for political reasons that's fairly unlikely to happen anytime soon.

[0]: https://assets.science.nasa.gov/content/dam/science/esd/eo/i...