None of these (and other) schools view endowments as something to spend. It must always be growing to show how amazing and great the school is.
I remember how during the pandemic there was a number of articles about how these schools might have to take out some small pittance of the endowment to fund certain things and the schools were all doom and gloom about it.
Many endowments pay the salary of the fundraisers at major universities, in fact. And legacy gifts are usually set up for "forever" scholarship, where, say 5000 bucks is available for a certain type of student each semester forever, because the gift to the school was large enough that they know investing it will make at least enough to cover the cost.
So no, endowments aren't spent, but the returns fund a lot of stuff.
It is the SI prefix for giga, and commonly used instead of B for "Billions" outside of the US when writing "Harvard's endowment fund is currently worth fifty-three billion US dollars".
Look at the worth of theirs endowment funds at the end of 2021 :
Can you honestly tell me that they need more donations ?