I've never lived in a country where carrying gun is allowed and im not much familiar with the topic, so I won't comment on that. But I lived through the time that there was no phone and then when there were phones with non of these junk apps on them and now. This, I believe, makes it very clear, what the real cause of these problems is.

It is certainly a stronger argument in the gun case, since defensive usage significantly outweighs criminal usage and most people don't even shoot anyone. Here we're dealing with a situation where being addicted to your smartphone is the norm, not the exception.