I am strongly in favor of getting my elementary-aged kids up earlier in the morning to allow high school students to start the day later. If you google the phrase "teenagers sleep," your top result will be for the National Sleep Foundation, which states:
"If teens need 8 to 10 hours of sleep to do their best and naturally go to sleep around 11:00 p.m., one way to get more sleep is to start school later."
The science is clear. Teens may be larger than younger kids, but their physical size doesn't make them less vulnerable. And even if we take away their cell phones at 8 p.m., they may not be ready to sleep until much later. That is just how teenagers are wired.
One day, my kids will be in high school, and I hope they'll arrive well-rested and ready to learn.