It's the last mile that's the issue.
You can find gigabit business internet basically anywhere.
I have a friend whose parents live in rural Kansas who to this day can't get more than dialup or satellite, even though they've called up every single semi-local ISP (way more than once) and said they'd be willing to pay for installation. At this point, they have more than $20K saved for the chance that some company says maybe.
It's simply way more complicated than you're making it out to be.
Found it: https://www.compareandconnectk12.org/
So your friend's parents' $20K gets them a kilometre of dark fibre. Maybe.
Edit to add: point-to-point wireless links might work better, but there again for a reliable wireless repeater you're looking at tens of thousands of dollars minimum in a rural environment. And in Kansas you're going to get bad Fresnel occlusion, so you need really big towers.