I once said it as it is: I'm not interested in spending time in them (social networks), I'm not interested in entering them (logging in), which for me is a rather boring way to spend my leisure time. To those people with whom I wanted to continue communicating, I indicated the methods of communication that were convenient for me (for example, Skype, instant messengers).
Tell them that you are busy with work, you cannot be distracted, and there is only enough time for The Question. Moreover, if there is no time for The Question either, and you take time off from work to write a question or an answer there.
1.Tell them that you are an introvert! 2.And you consider communication in social networks an unceremonious invasion of personal space ...
3.Can you say that you will also experience an information overdose rest is necessary.
You will lose some friends (if you do not use messengers yet) because a telephone conversation is a discomfort for many nowadays.