Endowments are the way of the world. Even Lutheran churches have latched on to the idea to uphold its institutions because it seems so powerful. It allows for paying and supporting for something in perpetuity, just living off the interest which the large endowment principle throws off.
Money given, whoever, should be given to to be used. The main principle of an endowment must be untouched, so that it can keep giving off its interest.
Christ will return to judge, so every endowment, as all money and wealth, will be worthless at some point. So it is never full used and put to work in this world. It value comes in its timelessness—which is contrary to the Christian conception of time and wealth.
There is also something to be said for not relying on savings, especially for churches. The pressure to raise funds—and depend on God’s generosity through people–is healthy and may provide some measure of accountability. –ed.