Social media is fake attention, but people don't normally see this for what it is. The interaction on the social networks is not the same as face-to-face contact with an actual human. Because there is so much stimulation on the internet, people think this is the same as the real thing, so they have less of it.
No, for most children and teenagers, social media enhances person-to-person contact rather than replaces it. Nowadays as in the past, reclusive children have a tendency to stay at home, while outgoing children get out more. Teenagers and children use social media to keep in touch with friends and make appointments to see them physically. Most young people do not use social media as a substitute for personal contact with friends.
Social media does not replace person-to-person interaction, it helps it along. When kids participate in social media, they can be in contact with friends and family even when they're far away. They can still hang out with their friends in person, and social media can help facilitate in-person group activities by bringing everyone together easily and conveniently.
Social media has not led to less person-to-person contact for teenagers and children. It has led to less meaningful person-to-person contact. Children and teenagers see others at school. They sit in classrooms with them, move through hallways, eat lunch and (in the case of children) play on school playgrounds together. This is all contact. The problem, however, is that there is not much opportunity during an average school day for meaningful interaction with each other. Children and teenagers try to make up for that lack of interaction through social media, which is a convenient form of communication.