We got ours when we were spending a week at Catcha, there are no phones in the room there.
I like to have the ability to make a phone call when I need to and have a way for people to reach us as well.
With that being said, I think the only time we used our cell phone the first time was to call Terry and Janet to make arrangements for where we were going to meet
It definitely isn't a "must" have. Any restaurant or hotel will make calls for you.