I think it depends on how you view your phone service.
I consider phone service to be a life critical resource. I won't do anything that may result in me needing to place a 911 call at 3AM during a power failure and not getting dial tone. So far ONLY traditional land line works for that, at least in my area.
Cell phones work for many people, but coverage is so spotty where I live that I don't even bother turning my phone on at home (if I do, the battery dies in a few hours). And I have experienced power failures of > 2 days where the cell towers started to run out of diesel and go down. Landlines do not go down; they keep about a week worth of diesel on hand and even in extreme power failures, they will truck in diesel to keep the switching stations up.
I actually use Google Voice so I don't pay a dime even if I spend all day talking long distance (domestic) and if I ever called internationally, it's 1 or 2 cents a minute to most countries. But it uses my standard land line. Google Voice is kind of nice in that it gives me pretty much all the features I could ask on a bare-bones phone line - I don't even have to pay for caller ID, I pick up the phone and their computer tells me who's calling, and I press 1 to pick up and 2 to send them to voice mail (it'll go to voicemail on its own otherwise). Also I can see records of every inbound and outbound call, and they transcribe (speech to text) voicemails and email (or SMS) them to me.