Well considering that public schools (at least in the US) are glorified daycares in place so both parents can go work, the obvious solution is to globally push back the concept of “morning” to mean ‘a few hours after the sun rises’.
What if (hear me out) the high school kids can go to bed earlier if they’re sleep deprived? Waking up at a certain time is really only half the equation. The school isn’t making you stay up and get up early.