I think there is some nefarious reasons for the current setup but here’s a point I didn’t see. People and children especially can’t learn for 8 hours straight learning needs to be broken up with play time or eating or socializing. Then reinforcement of what you learned earlier before you go to sleep can be helpful. Ideally I don’t think homework should be learning new subjects or really hard at all it should be a cake walk of whatever was learned during that day.