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.