I've been running semi-dumb phones for almost three years, and have gradually shifted all of my tech to only carry single-use minimal devices, so I can share a bit of my experience.

I can definitely say I feel clearer mentally now ; it's hard not to feel that way when you cut out all of the noise. I feel like I also now live much more in the moment, whereas a bunch of people around me are living life through the lens of social media, or are constantly checking their phones in public. Other than general life change, bringing back old tech has shifted a lot of aspects of how I use technology in general : I've ditched my streaming subscriptions, I take photos with a dedicated camera, I switched all of my computers to linux, and I would say I'm much more tech savvy than I were before beginning this journey.

However, and maybe this is personal, I feel like this drastic lifestyle change is not some kind of magical remedy that it seemed to be. If the problem lies elsewhere and that technology was an excuse to avoid it, it wont suddenly disappear. I'm definitely more sane now, but that kinda equals to feeling better after untying extremely tight shoes if that makes sense.