I don't know for sure how many iPhone users have ever plugged their device into a computer for anything other than a quick battery top up, but my hunch is most people just don't sync phones with computers any more, they sync them with iCloud or Google. I don't own an iPhone, but I've never even attempted to synchronise my phone with my laptop - contacts, calendar, and email come from Google, music from Spotify, and video from Netflix or Amazon. The closest I've come is copying some photos off the SD card.