Apples eco system does have pretty good safety features. As far as I have heard, Apple is indeed not up to sell user data outside their eco system. However, they collect data from their users and use it for their own purposes. It is always a good advice to go through each setting (of phone as well as laptop) and evaluate if it is needed for functionality (e.g. location services or access for the camera or contacts). Not only will this measurement reduce the amount of (usually) unneccessary data that is being transmitted otherwise, but it will also improve battery life as well.