I ask because I don't really know. Buggered if I know. I'm sure there's a reasonable and unreasonable point (fiber is expensive and it's really expensive to maintain it up here) and I'm not quite sure if I'm past the unreasonable point or not. I am not even the most remote. There are people, in my State, who are more remote than I am with *miles* of phone line that may have not been really touched in 50 years except to do repairs. What does unreasonable look like?"
There IS a point where unreasonable does become a thing and it sounds like you are taking about a location where people have moved because they don't want to be connected to the world. Internet has reached the point where it is essentially a utility. If you don't have fast access you don't access to a full compliment of education resources for your children. When you ask questions about the world you just continue not knowing the answers. When politicians rile people up about issues only the uneducated and uninformed could possibly believe people don't have access to information and remain uninformed when they vote for those people. In the modern age there is no excuse for people who might well vote getting their information from blatantly misleading and bias sources like CNN and Fox News.
Like it or not internet is a utility. I agree there is a reasonable line, some parts of Maine and most certain other remote mountain areas are likely unreasonable for any sort of "wired" connection. But fiber isn't more expensive than copper, it's actually less expensive. Copper is a semi-precious metal worth too much to make pennies from and all the copper pulled down can be recycled. Fiber is made from the second most common element in the earths crust. Fiber doesn't suffer from electromagnetic interference so no "noisy" lines and it be put in runs up to 1500 miles whereas copper requests powered junctions on the order of yards. Fiber is much cheaper than copper and much cheaper to maintain. The cost is just putting it in to begin with. And will be the medium for future technologies for the foreseeable future, trying to squeeze something more out of copper a magical dance that has been impressive but is definitely at it's end. So, if it is reasonable to run any sort of utility line out to you, I see no reason it isn't reasonable to run fiber lines. Especially when you and other americans have already paid for it. I'd say so long as there is a place we've already paid them to run fiber to that they haven't run it, then it's more reasonable to run that fiber than for them to pocket the money. And no, it's not just tax cuts on profits from phone bills, the telcos were given over twenty billion dollars in tax credits not just deductions.
There are places where even that isn't reasonable. At that point yes there are sat links, they suck but they work. But there are also designs for tough blimps that are a little closer to earth and efficient enough to float for 6 months at a time. A good sized network of those flying all over the place and they get crazy line of sight.