I did this for 3 years and reluctantly got a smartphone again after service / voice issues on my dumbphone. Critically, my dumb phone had no browser at all but could hotspot. I would bring my laptop if I knew I needed connectivity. The phone could only do phone calls and SMS/MMS.

I think the long period of actual inability to use apps was extremely helpful in breaking the habit. When I got a smartphone again I immediately uninstalled/disabled all apps including the browser and have had no desire to enable them. It's effectively a dumbphone but with hardware/software that is reliable and a good camera.

It was inconvenient but I came to appreciate it even the inconveniences for the reconnection with the world. For example, I planned a motorcycle route and printed/memorized the directions. It made the trip more enjoyable using my navigation skills and not hearing a a digital voice giving me directions.

I used a Jethro SC490 for those that are interested, it lasted a few years and a replacement battery is cheap.