Fundamentally, it's because we're tool-using primates. For most of human history we've created things to use on other things to do things. Selecting an app isn

Fundamentally, it's because we're tool-using primates. For most of human history we've created things to use on other things to do things. Selecting an app isn't any different than selecting the right tool for the job at hand. In this analogy, your phone' s homescreen is your toolbox - here are all the things you can do. Personal preference and the specifics of the task count for a lot which is why there's many types of hammers and apps with similar functionality. From a toolbox perspective, performing an action on a contact - e.g. calling or texting - only involves a few out of the many tools available and therefore shouldn't be the sole way to navigate the system. However some contexts a person-centric UI is great, and one of iOS' failings. I should be able to go to a person in the contacts app and see all the available ways I have of contacting them depending on what apps are installed. Maybe when AI becomes so good it knows what I want to do before I do, or when we've evolved to the point we no longer feel the need to hit things with other things, a tool approach won't be necessary. But I think it will until then.