I had researched dumb phones recently only to learn that the two most important functions of a smartphone (for me) is the GPS and having a decent camera, and these things are either crippled or missing entirely from dumb phones. It's simply easier to dumb down your existing smartphone, especially if you have an Android phone.
In my case, I have a 2017 Pixel 2 XL running LineageOS, with a text only home screen launcher (OLauncher). I only have SMS, phone/contacts, camera, open street maps, KOReader, Music, Podcasts, Notes, and Calculator. That's it. Everything else has been purged or disabled, including the web browser, via ADB.
I don't really use it all unless I'm driving. I wrote about my setup here: https://chuck.is/phone
In my case, I have a 2017 Pixel 2 XL running LineageOS, with a text only home screen launcher (OLauncher). I only have SMS, phone/contacts, camera, open street maps, KOReader, Music, Podcasts, Notes, and Calculator. That's it. Everything else has been purged or disabled, including the web browser, via ADB.
I don't really use it all unless I'm driving. I wrote about my setup here: https://chuck.is/phone