As a current graduate student at one of the top four, a couple things to consider are 1. Total investment per student, 2. Age of university, 3. Amount of research.

For undergrads at my school, basically no low income students have to take loans because the financial aid is very, very generous. When I was an undergrad here (grew up in poverty) I had a living stipend when I wasn't in the dorms. My university is also among the oldest in the country, and time for the endowment to grow and compound is relevant of course. And my university has a number of large and highly productive graduate schools associated with it, not sure if the student numbers are only undergrads or all students. They also have a bunch of community programs and stuff, for the city and whatnot, so there's a lot going on here. And I know for my university at least, we are pretty physically constrained in terms of literally housing undergraduates. Couldn't admit a ton more if they wanted to, and even then the last few classes have been record sizes.

I just wanted to point this all out because people often see numbers like this and freak out that certain universities have "too much" money. Even people at these universities, haha. But the thing is that the point of the massive endowments are that you aren't spending it. Returns on that endowment are what allow for the economically sustainable development of the campus and help fund the huge amounts of academic work that come out of these institutions. They're spending a lot each year. A bit different from the issue of stupidly wealthy individuals hoarding money to grow their net worth only.