I'm still using my "dumb phone" from 2010. I like it cause it has a physical keyboard, a long battery life, and I can drop it without worrying about breaking the screen. Plus I don't have to worry about the privacy issues that come from apps collecting data.
Honestly the only feature I feel like I'm missing out on is GPS. But I've actually found that not having GPS improves my sense of direction, since I force myself to actually learn the map of my surroundings instead of just always relying on the phone.
The two things I've missed without a smartphone is maps and the ability to find phone numbers and addresses of businesses on the fly. Other than that, there's no substantial reason to carry a smartphone. It's funny how much R&D was used up to build what essentially is a digital phone book.
I, on the other hand, don't use it to find phone numbers and addresses of businesses, but use it all the time to download and listen to podcasts. Each person might only have a couple of important uses, that doesn't mean the total set is small.
Honestly the only feature I feel like I'm missing out on is GPS. But I've actually found that not having GPS improves my sense of direction, since I force myself to actually learn the map of my surroundings instead of just always relying on the phone.