There is a presumption here that all people are slaves to devices. While many are - I’m aware of that - it is definitely not all people. I know no one among family or friends who is adult who has a problem. Grandkids are a different thing.
I’m of the generation who developed all these toys, I worked with or wrote about IT and lifestyle technology for decades before moving on to senior management in publishing. In our organisation, those who are “addicted” to devices all seem to lurk in our graphic design studios. They also play digital games incessantly.
What has not been mentioned is that modern devices have the ability to schedule active times. With Apple devices it is a “Do Not Disturb” option. Mine mutes all activity between eight PM and seven AM. No calls (unless on a white/favourites list), no texts, no notifications, no email. I do not look at my email or messages until I have my first cup of coffee in my hand.
As for Blue Light, that is an old and well recognised issue. F-Lux et al was developed to combat it. Apple now incorporates a timed version of the same thing — kills all blue light to a schedule. I do use a device in the bedroom, to play music or one of the sleep apps that use audio ambience to relax and promote sleep. I find them effective.
When it comes to Grandkids and their obsession with iPads etc., the fix is simple. I set up timed access using our router. Now when they visit, no matter how sneaky they get, they can’t get online after seven in the evening, or before seven in the morning. They adapted quickly, and don’t bother trying their online games during the hours when they know the device won’t work. (They are five & seven — once they get older clipping their wings might take more effort.)