Yes, I think it depends on the kids and the courses taken. My kids have gone for the most rigorous classes possible. This suits them. They are both really dedicated ( not my DNA). I’m the good test taker. LOL. But a lot of time is spent on writing assignments and projects. One kid spends a lot of time on Latin and the other spends a lot of time creating colorful notebooks for Bio. They end up with great grades but not every grade is a good one. There are bumps and lessons learned.
The teachers of high level courses also stretch kids who are doing very well. A history teacher might get the kid to join debate or write a paper for a magazine or help tutor someone and a science teacher might have the kid work on a project with other like minded kids. So the work does add up. Usually this work is outside of classwork but kids build interests which seem to help them discover what they want to study in college.
There are some kids who stay up until 3 AM(or later) to stay in the most rigorous classes. These kids seem to be hyper-focused on GPA and often want to compare notes grades (which my kids won’t do). I can’t say I would support too much studying for my own kids. We’re paying to send them to BS’s so they can have fun and learn. Balance was key in all our decisions. Oldest actually chose current BS over another more famous name. This was done intentionally in order to have time to pursue an interest.
I think I saw a rubric of homework from PA/PEA once and it was a big number. I don’t know how that compares to other schools but I’d imagine it’s about the same. All of these schools have advanced/AP classes and all have overachieving kids so they need to do a lot of work.