I think it's driven from an understanding that being constantly connected is potentially unhealthy for ones mental health. Not saying that's 100% true but I think enough people feel it that they are looking for solutions in things like dumb phones, digital detox, purpose-built devices etc.

I understand your lament about people just being able to be bored, but I think this gets at something deeper, that when we aren't bored and do want to do something, we are often distracted because of the nature of smart phones.