Seems to me that universities think the purpose of high school is to prepare students for university. It's not. With fewer than 30% of high schools students going to university, a high school is not a prep course for university. Universities need to get off their high horses and realize that the lack of student success in university is not poor preparation by high schools but rather the poor learning environments of universities. University professors have never attended teachers college. They have never studied the craft of effective instruction and assessment. And they have never practiced researched and tested strategies.
So no, high schools don't prepare students for university work because I don't think anyone can prepare students for such appalling places of learning.