Ideal support at home in some cases. Being allowed to rest and sleep as needed, good food around, transportation to help minimize commute times, etc. Having this makes it much easier to meet the demands.

Not in all cases. But there are absolutely logistical advantages some kids have and others don’t, and some kids suffer significantly for that disadvantage.

Always exceptions to rules of course. And humans can still do impressive things under duress. Maybe the question is not how do they manage, but how much better could they manage under more ideal schedules, and how many more kids would do better as well?

Chronotypes are a spectrum, probably roughly normal distribution. So ~25% are going to be in the left (early) quartile and will be fine.

And of course, even I as a pretty severe nightowl learned some things in school. It was just that I was constantly falling asleep and always sleep deprived and had to catch up on sleep every single weekend. I likely would've done much better had school started 2h later.

Yes, high-achieving teenagers are mostly tired all the time