I don't live in a mountainous area, and I still have a landline. We're rural, with only a few cell towers so reception is bad for cell phones. Without a landline, we'd have no access to emergency services because you'd have to go down the road to get reception on a cell. Plus, our Internet is done over those old-fashioned phone lines, and getting rid of the phone service makes it cost a lot more. Many of us can't afford satellite Internet, either.
So, even though some of you can't imagine such a Luddite life, many people even in America are using the old tech, some out of preference and some out of necessity.
As to the OP's questions, I don't know about forwarding calls to cell or otherwise, as I haven't done it in years, but the ringing sound doesn't last that long when calling, not nearly two seconds.