I spend a lot of time all day on the phone at work, but when it comes to private phone calls, I have never had the sort of thoughts expressed in this thread - I am amazed! Admittedly, the phone doesn't often ring at home, but if it does and it's a near or dear one, or even if it isn't, I drop everything to talk to them (well, actually, I carry on, if I'm doing something like sorting the washing or peeling potatoes, with the phone tucked between ear and shoulder - I wish I had a headset like we do at work, to prevent cricks in necks and back problems.)
My mother, who is 95, enjoys chatting on the phone in the evening, but has remarked that no one phones her - it's always her that rings them. I phone her every evening, but if she wants to talk to her sister, or her recently bereaved neighbour, or her nephews or nieces, she has to make the call. She was a secretary all her life, so phone conversation is quite natural for her.
Before the internet, talking on the phone to someone you didn't know was a great way of getting to know them without the inhibitions or prejudices that can be caused by their appearance, which might colour your opinion of them if you could see them.