My FIL runs an electrical co-op in upstate SC. He had the choice of creating a new HQ for their co-op, or run fiber to all their customers.

He ultimately chose the new HQ because the cost-per-mile was insane when you got in the more rural areas, and he had no guarantee that all serviceable addresses would subscribe, plus it would increase costs for all their subscribers even if they didn't join their network. He also afraid that something faster or more efficient than fiber would become more widely available over the next 10-15 years and then their network would be obsolete.