Fir is used in the US (most commonly in the pacific northwest), it's just typically used for outdoor construction because it doesn't warp as easily and holds up far better outdoors than pine. So you will frequently see it used as decking, fences, or siding (although wood siding is getting pretty uncommon).

Fir is also sometimes used for framing like pine is but pine is usually cheaper. The only advantage fir has over pine for framing is that it tends to be a bit stronger. But there are very few places where you need that extra material strength and can't just use slightly more reinforced pine construction to acheive the same result.