Yes and no.
Certainly the schools above (and many others) have plenty of money in their endowments. They won’t be running out of money anytime soon (or ever) and have no trouble covering the costs of operations and programming at the school.
And yes, they do spend what they can first of the restricted funds before turning to the unrestricted.
But the interesting point to me is that, over time, many of the older restrictions have left the schools with gifts that are grossly underutilized both because of the restrictions on those gifts and their growth over time. Donor intent and state law make it nearly impossible to use some of these restricted gifts in certain states.
And on top of that, some of those funds may be part of the “permanent endowment”, which prohibits the use of the gift corpus and limits its use to the gains only.
In the case of PEA above, 26.61% of its endowment is designated as “permanent endowment” and therefore untouchable. That’s $404.2M.
Again, to be sure, you could run a fine school using nothing but tuition dollars and the annual investment returns from that sum, but that’s not my point.
My point is that independent school endowments are interesting and fun to compare, but a comparison of the top-line numbers only leaves out a big part of the story.