If you have troubles with notifications; I beg and implore you; Learn about how to train your device! Learn which applications are sending notifications, how to block apps that send unimportant notifications, and most importantly how to manually silence your device when you are not in a time or place you are willing to receive notifications and how to un-silence your device so you receive important ones as well!

This is not anywhere near as simple as you make it out to be. I'm tech-savvy, ensure my phone is configured exactly the way I want it, and do not have any issues with phone addiction. However, I am still constantly annoyed by unwanted notifications. App updates regularly introduce new ways to notify you that can be disabled, but are defaulted to enabled. Also, many (most?) apps do not allow fully granular notification adjustment and just smash most things under "General". I may want GrubHub to ping me when my order's on the way, but I do not want them pushing promotions at me. (Note: I picked GrubHub at random, but my example is actually 100% true. The only way to get away from their promotional notifications is to disable all notifications.) I absolutely understand the desire to just get away from the app world entirely.

My wife has the same phone as I do. She has no issues with using her phone, but I would not describe her as tech savvy and she really doesn't have an interest in learning all the ins and outs of every app. I don't blame her because my own experience proves that you can be a highly advanced user and still experience frustration. But, mostly, I don't think it's something she should have to spend time on. The general population is not going to become an expert on anything and default functionality should be catered to them. Currently, default functionality is driven by ads and engagement rather than usability, and I don't see that changing any time soon.

Choosing a dumbphone is a very valid way to just eliminate that issue entirely. It's not a lazy choice, it's a practical one about how one wants to spend their time.