I came to the very same conclusion - I need "empty time" to reflect, and prepare myself for my own life. For me, it was not smartphones, it started with books when I was a child, and continued with music players and alcohol later. Everything to keep the unwanted thoughts and feelings at bay. I am an excellent daydreamer as well, at times of stillness, I find something to "work on" in my mind.
What I ended up with is literally a time of day where I "sit with myself" and just think about things. I just sit down for some minutes and try to get my bearings on where I am in life right now. Also, I eliminated a lot of background noise and music - I often do menial things without any other distractions for example. Good opportunities to think about something deep.