Alexis Madrigal explains why it is sometimes hard to get phone calls answered, and why you might not feel like answering your own. As he notes, the sheer number of alternatives to the vanilla phone call have rendered it "a vanishing cultural layer". Having so many communications options (email, text, phone, messenger, snapchat, skype, etc) does create a complex landscape where different people are approachable only via specific avenues, and if you try the wrong one, a reply might be slow in coming or nonexistent.