For the record, my wife never adopted smartphones and thought they added no benefit to her life, and was told she would be "left behind." Today she lols at all the articles talking about how "we are all addicted to technology" and she think it's funny the "digital minimalism" movement is trying to live the way she does.
"You're going to be left behind" is a marketing slogan that targets your inner FOMO. The truth is technology either serves you or doesn't. They were probably telling each other that while drinking the Kool-aid at Jonestown 🤷‍♂️