I can get this, personally I don't really care for the sandbox in this game myself and that's actually because of the prologue. The prologue just feels smooth and was perfectly fine way to go about things, where as I find the sandbox empty and more content filler than actually something that's needed.
I say if you can remove a system in a game and it wouldn't change anything then why have it at all? For the phone? We can just have a icon like the relationship stuff that we can click at any time. To make the world feel more immerse? I feel it's much to empty for that if anything minus the school it makes the big city feel dead, and points it out instead breaking immersion.
But What do I know at the end of the day, I don't have experience actually making games afterall. I just pointing out how I felt after playing most of the night myself.