One of the most interesting things about a hardware based restriction is that it entirely avoids the game of turning on and off apps or deinstalling them. Even if you want to respond to a message in your DMs in Instagram, it will work, but the temptation to pull up the Reels or For you page just isn't there when it's all black and white and choppy.
Mind you we are super early stages but the idea feels promising and by my own testing I have really found it to be a much more pleasant phone experience.
I'll post some links here if people are interested.
Similarly (easier but less drastic) I’ve seen people turn their phone to grayscale mode to make the device less engaging and remind you that it’s a productivity device, not an entertainment device. On iOS you can do this through the Accessibility settings. (Settings > Display & Text Size > Color Filters > Color Filters on, Grayscale
I would give a try to an e-ink based smartphone if there was a good one. The only reason I got a smartphone in the first place in 2020 was access to maps/taxi/banking apps which would work with any display. But given the grayscale experience I wonder if you get used to laggy e-ink videos as well.