I have a feature phone. I spend 40 minutes a day, over two stretches, where I'm away from a full-sized keyboard and large, readable screen. For my lifestyle, I fail to see the need to fill those additional minutes with connectivity when I might otherwise, you know, enjoy my immediate physical environment!
And feature phones still have the attractions for me that are mentioned --- relatively rugged, reliable, instantly resettable by popping out the battery, inexpensive to replace if lost or inadvertently damaged, etc --- even though I'm not out hiking.
What do I miss not having a smart phone? I don't have games at my fingertips. No big deal, I've never been too keen on computer games. I don't have a super-small screen that I can read an e-book on. No big deal, I carry a normal-sized book when I want to read something, and it's much easier to read printed text on a page. I can't keep in touch with my email. I'm not so important that being away from email for 20 minutes is a death-knell. I can't update my social media pages. Why would I want to do that on a small keyboard and screen? I can't have easy text conversations -- this is the only downside, and only because it seems most people these days spent lots of time doing that. But, instead, I can actually TALK to people (because my phone is, you know, a *phone*) that has a much higher communication bandwidth, and eliminates all of the tonal ambiguity of texting / emailing. Manufacturers can't market to me based on my instantaneous location. That's a plus. The authorities can't trace my precise travels over every waking moment. Also a plus. I need to be able to read, digest, and understand directions when driving rather than having a crutch tell me when to turn. All-told a plus, since it hones my ability to navigate by dead reckoning.
Did I forget something?
Oh, yes, I can't take decent quality photos. That's a downside. So when I know I want to take photos, I carry a camera that beats the pants off any cell phone (especially in low light), and deal with the low-quality snapshots that my feature phone takes when I forget.