Real social life vs Online social life

Everybody in 21st century has a mobile phone or something to call and to stay conected to social networks but is it necessary? A lot of teenagers say that they couldn't live without their mobile phone but most of conscient people know mobile phones aren't essential. My grandfather doesn't have one and he's still alive. Our society is fixed in a internet social world and I think it's more important to be sociable in real life than in social networks because you aren't talking directly to him and if the other person has a reaction for something bad or good you said so it isn't the same. A lot of peopleis talking with people online in social networks with people who see everyday but they never speak with them in real life. I think this is a big problem. It's funnier to have friends in real not in a screen. That's maybe the reason some teeneagers never go out with friends.