Cell Phone Tech - How Much is to Much?

Over the past ten years or so, we have seen dramatic technology changes in the way people use their cell phones. I remember getting my first cell phone and being able to do one thing, make calls. Shortly thereafter texting became the hottest new thing.
Now because i own an iPhone, i can do everything from shopping online, using a gps, playing music, pay for my starbucks coffee, to controlling my computer all from my simple little cellular telephone. However, when is enough enough?
Many people (like my mother) prefer not to have a phone like this. Both of my sisters, their husbands, and my father have the iPhone, and love it. My mom had it at one point, but then decided she did not want it anymore. She said it was because she just simply didn't need it, and it was too complicated to use, and she couldn't type using the touchscreen. Very interesting in that she went from the hottest piece of cellular technology, back to a simple little flip phone because it was all she needed.
My father, hated the iPhone when he first got it, not because it was hard to use, or because it was to weird to type on a touchscreen, but it was simply it made him to connected. He says he leaves it at home half of the time while he's not at work because he hates being able to see his work e-mail on the iPhone while he's say... on the golf course. He told me "there are sometimes i just do not want to be checking my e-mail, and sometimes i don't want the iPhone to check my e-mail either.
Is this just a thing of the past? Do older people who did not grow up with this technology prefer not to have it? It is interesting to me because if i do not have my phone with my, i feel like i am missing something. I like to be able to google something when I'm arguing over some dumb fact, or to be able to check the weather at a click of the finger. But some do not.
With all the new technology coming out in cell phones, things like projectors out of the sides of them, 3D  screens, and other ridiculous trends, it raises a question to me. How much is to much? Will there be a day where the cell phone is basically done getting add-on treatment? Or will there be one day where people like my mother won't be able to have just a simple flip phone? We will see. But as for now, some of this technology going into smartphones seems just excessive.