> The United States is 85 times larger than Switzerland.

All other things being equal; it's a lot easier to dig huge amounts of fibre runs (following roads) where there isn't a heavy density of people.

Distance is practically meaningless for fibre optic cabling, but digging up historic cities, digging through mountain ranges, avoiding subways, plumbing and ensuring you have enough cables for the density of humans is hard.

Much harder than running cables between buildings that house 10 people which are 50ft away from each other.