It's difficult to turn your phone off if you have a spouse or children or other dependents who you can't drop communication with for hours at a time. But it's helpful to strip it down to the essentials so it doesn't double as an entertainment device.
To be sure, you absolutely can do this. I did it all the time as a kid. Nothing bad happened from being out of constant communication for hours.
You are focusing on things that never happened or never will happen.
Phone is not the only communication you need for your kids or spouse.
The need to be instantly reachable at a moment's notice is a modern anxiety that we successfully lived without until the mass penetration of cell phones 20 years ago. Your spouse and children will manage without being able to text you for a few hours, just like spouses and children did for the first 100,000 years of humans history.
It is in actual fact not difficult to "drop communication with for hours at a time". This was the human norm for millenia, up to a decade or so ago. And given the toxic side effects of all this communication it's probably going to have to be worked out again.
We raised a child with the principle that "No News is Good News". She turned out great! And she lives that way still. That constant level of screen stimulation is strictly not necessary for family happiness, and I think you all who think so have not really internalized what it means for a child to learn responsibility.
See also free-range kids, and the social insanity that causes kids/parents to get arrested for eg playing in a park alone. There's a bunch of mental illness out there, and the screens are big reason why.
Oh right. My beautiful daughter reads books constantly. Weird that, huh.