Wow. This is a massive figure.
The US GDP is $30 trillion but most of that is spoken for; it's wages, costs, reinvestment — money that's already doing a defined job. But this $3 trillion is different; it's flowing through entities that are completely exempt from normal market pressures and competition.
What's insane to think about is the composition of it; this isn't charity money, it's Medicare reimbursements, government contracts, university tuition, hospital fees. Which means the most important sectors of the economy — healthcare, education, research — are basically being run by nonprofits. Enormous institutional players with massive lobbying power, operating in markets with no real competition.
It's less that profits are being funneled into nonprofits and more that entire industries have reorganized themselves around the nonprofit structure to avoid the accountability that competition normally creates. Which explains a lot about why the economy feels so captured and doesn't make sense anymore.