I don't think it's a mistake. You are free to have your own preferences but to pretend that there is no perceivable utility or appeal to smart phone when compared to a classic cell phone doesn't seem like a realistic stance in my opinion. Not valuing the greater utility of a smart phone in light of the downsides can be a rational exercise of personal preference.
Lol, I can see the utility of having a car but I don't own one, same for cable TV. I could name a bunch of other things others can't live without which I eschew but I don't deny that they give pleasure and utility to those who possess them I really don't question tour decision but to say you can't see why someone would have a smartphone is silly. Edit And sorry that I'm at work and can't read whatever's being said on other parts of the post.