"10+ years ago we didn't use smart phones and we coordinated the rest of our lives just fine."
This argument is ridiculous. It assumes that nothing in the world has changed, which is obviously flawed.
It's like saying that people didn't use cars in the 1830's and still got around just fine, so why should we be using them now?
Progress and innovations are made to make things easier and more accessible. Rather than carry a 12 month calendar around everywhere you go, or a planner as a separate book, now you have your email, calendar, to dos, notes, voice recordings, phone, etc all in a single device that fits in your palm. No more need for a briefcase worth of crap. Just a single phone. Sure people got along find 10+ years ago, using the best that was available to them at the time. And so should we.