How do college professors deal with kids whose high schools did not prepare them sufficiently?

I am a recent college graduate who was talking to my teacher family member about the way high schools seem to actively set you up to fail in college and how college professors in my experience don’t seem to have much care about this.

I was wondering from teachers how you feel about the fact there seems to be such a disconnect between what is expected in high school and in college.

I’ll give some examples from my own time as a student: in high school I was never asked to write a paper longer than 2 pages, I was never taught to cite sources in any format past MLA, nor had I been asked to read a full book. Then in college in my first class I was asked to read 2 books, write a 12 page paper, and use citations I had never learned or knew existed. Similarly in high school math I was taught to use only paper and extremely long handed math, the second I got to college most of my math professors expected me to understand online math tools and formulas I had never seen in my life. There were also multiple times entire lesson plans in college had to be thrown out so that my professors could teach the class some important idea or format that high school did not teach us.

So what causes this disconnect? Is there a way to fix it? Or are students like me just destined to spend their first 2 years of college relearning how to learn?