Fwiw, Saturday classes at schools that have them have been good at making Friday night less of a time for getting into trouble. It’s also a good way of getting day students on campus for at least 1 weekend day as most stick around for afternoon activities, planned and ad hoc. Schools can schedule one of the weekdays as a shorter day and do sports competitions on that day and Saturday so there’s little interference with the academic “flow”.
They are particularly challenging for kids who have an elite sport or EC off campus. They also make going home for the weekend hard for all but the most local boarders. The former applies to only a handful of students while the latter can be an advantage to those who live far away.
Not sure where you are, @GPS, in your thinking about this. My kid hated the idea! But I have come to realize it’s a bit more nuanced than just ckass schedule.