First off, I think you're misinterpreting what I mean with 'misuse'. I meant it in the context of 'health', and I don't really care what the intended purpose was. The television, for example, is a great invention and I love watching shows and movies in the comfort of my home. You could say the 'use' of a tv is that you watch as much as possible so advertisers can make money. I think we can still agree that watching tv all day is 'misuse' when it comes to your mental or physical health.

Second, 'content consumption' is a bit vague. I'd say a smartphone is worth having because so many people use whatsapp instead of sms, because it has google maps, because I can check my trello board occasionally, because I can check the weather, and very frequently to find out how to get from A to B using public transport. None of that requires me to be constantly 'consuming', but it's still very useful.

In fact, For a full two years I had a smartphone (Nexus) with no data plan, and it was still worth having. It functioned as my calendar, notepad, dictation device, and even maps (although it is less useful offline).