Is smartphone/digital screen attributable to some degree to teenager's late-night habits, and therefore a need for later school times?
I was an avid reader, and my best opportunities to read were late at night. I'd start with a flashlight under the covers, but I found out that the best way to slip by was to go into the bathroom, lie in the dry bathtub with the light on, and read for as long as I wanted. It worked fairly well for a while, I guess. My mom went absolutely nuts over that strategy though. I suppose I was about 10 years old at the time. Later on, when I was 16, I had a so-called "girlfriend" and I would fall asleep during late night phone conversations with her. Or I'd go visit her house and come home late at night.
In high school, I was beginning to feel the onset of a chronic major depression, and I absolutely could not wake up on time. My hair regimen took 60-90 minutes to fix up in the bathroom, and by the time I was driving myself, I found an 11-minute route to rocket to school as fast as possible. Most of the time, it would be my father pouring cold water into my face just to get me roused out of bed. Therefore, mornings became an absolutely traumatic time in addition to all the other childhood traumas I was undergoing, and it took me decades to recover from that.