> The old "i'm a philanthropist! (and totally not doing it for the tax breaks)" nonsense,
How does this work? Suppose that someone donates $1 million to charity. They don't pay income tax on that money -- but they no longer have the money. I suppose that they could try to get clever about it by making a "buy yachts for our donors" charity, but that's explicitly illegal under the 501(c)(3) requirements.
Big donors do effectively direct the agenda of charities, and while direct “buy yachts for out donors” things are usually hard to get away with, there are lot of other ways for charities to be used for donor personal benefit, e.g., as a vehicle for social influence operations, political (as long as it isn’t too nakedly and specifically centered on a specific election) and commercial propaganda, and other things rich people would spend money on to benefit themselves and the businesses from which they derive income with or without a tax break for doing it.
often they'll loan out pieces of art to museums, so they get the tax benefit and they get to keep the art pieces. I'm not sure how many of them are giving cash away to non-profits they don't have some controlling interest in (seems it would be rare but maybe I'm wrong)
You're somewhat misremembering a real thing. It's possible to profit by donating a piece of art to a museum and claiming its value to be much greater than what you'd get on the open market. This is tax fraud, though, and the IRS will probably notice.
How does this work? Suppose that someone donates $1 million to charity. They don't pay income tax on that money -- but they no longer have the money. I suppose that they could try to get clever about it by making a "buy yachts for our donors" charity, but that's explicitly illegal under the 501(c)(3) requirements.