There are many incredible benefits of a smartphone. I need not tell you b/c you probably have one and likely are reading this on your device.
I am not minimizing the benefits.
But I DO want to make a point.
When frum kids go off the derech, in approx. 100 percent of the cases, one of the first steps is to buy a phone.
In other words - when a person wants to abandon Hashem and religious observance and jump into a lifestyle of מילוי תאוות [gratifying desires and lusts], a basic step is buying a phone.
That says a LOT.
I Baruch Hashem don't have a phone, have never had a phone and hopefully will never have a phone. Not b/c I am a Tzadik. On the contrary, I am much closer to the other pole. But I find that people with phones often lack menuchas hanefesh and are constantly involved with their phones. Not walking around with a phone allows much needed peace of mind and allows one to focus inward and not outward.