[curun1r]

A lot of that is sleep hygiene. People rarely had issues falling asleep early before electrification. And we’ve made it even worse with TV, computers and smartphones. Being very conscious of light consumption and turning off devices several hours before sleep makes it pretty easy to fall asleep earlier.

I’m one of those people who normally can’t fall asleep before midnight and struggles to wake up early, but I’ve done a few digital detox programs where I’m without any electronic devices, and I’m always amazed at how quickly I fall into a schedule where I’m asleep before 9 and waking up at 4:30. And it’s also amazing how much better I feel both mentally and physically when I’m on that schedule.

[Nextgrid]

In my opinion teenagers need time for entertainment and socialization. When adults do it it's normal but when kids do it it's "TV bad, computer bad, smartphone bad".

If you assume 8 hours per day for school, maybe one extra to get to/from school then homework and house chores, how much time does that leave for entertainment?

No wonder kids stay up until very late because that's the only time they actually have for themselves to do something they actually enjoy and is not being forced upon them.