I did exactly that. My daily carry is the new Nokia 3310. It was $90. It's fine. I can lose it or drop it and not care. And it's small!
Learning how to type a text again using the numpad was painful, but after a few weeks I was back up to speed.
No Facebook, Slack, Email. Not even a browser. No distractions.
When I'm out with my kids, I'm with my kids. When I'm working, I'm at my desk with a real computer.