My other half has had every model of iPhone from release and still has them all in pretty much mint condition and all have never had any app installed on them.
She uses her iPhones (currently a 32gb i5) for calls, texts, email, pictures and listening to music and that's it, it's a device to help her live her life simpler, not take up extra time occupying her on other things.
My 4s only has 3 apps on it, Nav Free, Barclays and MyFitnessPal, as I have much the same perspective
One of my aunt uses her iphone without any apps; only make calls, take pics, and web browse. Has been doing this for 2 years.