When you have a landline that still happens, but they call you instead of texting. It works great!
> the answer often seems to be a landline that you’re still available on. If you replace one phone with another, what’s the difference?
There are huge differences. Most of the problems with smart phones aren't "You can call people or get calls". A landline still allows you to make and take calls but avoids every other evil cell phones introduce into our lives. When you're available on a landline it's on your own terms, in a very specific place. Even having both a desktop PC/laptop and a landline, meaning you can take calls and look something up on the internet, is vastly less abusive and harmful than a smart phone.
What changed with the smart phone wasn't that you could go online, it's that the device itself is designed to collect every scrap of personal information it can and then funnel it to other people. It's designed to be as addictive, intrusive, and demanding of your attention as possible. It follows you everywhere, all of the time. It cuts us off from the places we are and the people we are with. Being away from a smartphone fills people with a level of anxiety that never existed with laptops and landlines and that isn't by accident.
abstaining from phones entirely or even setting boundaries and limits to reduce the harms they cause is realistic as evidenced by the people who do it successfully in reality. That doesn't make it easy, or even ideal in some situations, but it might be worth trying just to see where the pain points are and how they can be managed. You might be surprised at how much more capable you are at functioning without one than you thought.