Ahem .... Don't you use your smartphone to .... make phone call ?
I have: Phone, Contacts, Messages and Settings
Actually... no... most people don't make calls with their smartphone anymore. They'd rather use SMS or Messaging apps to communicate.
That being said... it's a bit redundant to have Phone AND Contacts in your dock. I always hated that iOS shoved the Contacts app down our throats whether we want it or not. It got worse when they shoved a dedicated Facetime app down our throats too. I can view/edit contacts from the Phone app and I can also initiate a Facetime call from the Phone app. I don't need all of these redundant apps/icons.