This can probably be addressed in itself by separating "aftercare" into an hour in the morning of "beforecare" in cases where parents really need to drop their kids off early. It's far from convenient for parents to pick their kids up at 3:30 PM, especially after waiting in a long line of cars, so we already have buffer times for that.

For a personal perspective, when I was in high school, if I had needed to take the bus, I would have had to get on it before 6 AM, since I was at the beginning of the route (first or second stop, IIRC). Luckily, some family friends had a daughter who was an upperclassman at the same school, and she drove me. I would guess there are few parents well-served by their teenagers getting up at five in the morning.