iPhone SE. I could probably go back to a feature phone if it weren't for the maps. But since I have it, it also gets used for:
Tons of web browsing. Mostly reading news but also the occasional YouTube rabbit hole or quick research.
Light email.
Transit status and info.
Listening to music on the go.
Default camera.
Slack when away from my desk.
Looking for or checking reviews of restaurants and sometimes other businesses on Yelp.
The occasional food order via Seamless or FreshDirect.
Casual gaming (puzzles mostly) when super bored or half paying attention to TV.
Testing apps my company built.
Scanning expense receipts.
A bunch of other infrequent miscellaneous uses.
For my use, the 5s was almost equally adequate, but I upgraded because I was constantly struggling to make space to download an app or song or take a photo on the old ones 16GB drive - and if I was spending the money, might as well get the newer hardware. The extra RAM allows a bit more multitasking without losing state, but a 64GB 5s would be perfectly adequate and less pricey.
I also have an iPad but mostly leave it at home and use it almost exclusively for Netflix and reading ebooks. If I need to get work done, an ultra-light laptop or netbook is 100x more ergonomic and barely larger or heavier. You can get an older generation one for less than a new iPad and it has better specs in everything except the whole retina screen deal. (Mine is a 2013 MacBook Air.) The iPad doesn't have cellular access either, so it would have to be tethered anyway.