Sort of related, but I switched from an iPhone to a Unihertz Titan with the goal of reducing smartphone screen time. Ultimately switched back to iPhone because I found that remaining connected to my social circle necessitated an iPhone. Of course, YMMV.
I switched from using an iPhone to something far less “smart” for about 3 months. Here's my experience.
tldr: I found that not using a smartphone is a lot more pain than gain. It's more rewarding to train yourself to use it wisely than not use one at all.
Over the past month, I've been uploading one-page reports on seminal papers in this field. The one-page reports are formatted in the following order: 3-5 lines summary, 1-3 major strengths of the paper (i.e., what's cool about this), a weakness, and future work opportunities. These reports are not intended to substitute the paper, but rather to peruse those with reports that spark interest. I intend to write and share more of these reports because it helps me absorb the material. My goal, other than writing better reports, is to start writing such reports on seminal papers from other fields too.
I tried doing that too, but to no effect. Ultimately, I feel that I lack your level of self-discipline when it comes to owning a smartphone. Therefore, in order to deal with perhaps my biggest source of distraction, and a large source of anxiety, I decided to ditch it altogether.
I transitioned to a feature phone from an iPhone to improve my overall well-being. The pros and cons list laid out above may be food for thought for those on the fence. Others may empathize with the approach of altogether abandoning rather than practicing self-restraint on a device ingeniously engineered to drain your attention.
Thanks for checking it out!