Private philanthropists have helped propel some of the most important social-impact success stories of the past century: Virtually eradicating polio globally. Providing free and reduced-price lunches for all needy schoolchildren in the United States. Establishing a universal 911 service. Securing the right for same-sex couples to marry in the U.S. These efforts have transformed or saved hundreds of millions of lives. That we now take them for granted makes them no less astonishing: They were the inconceivable moon shots of their day before they were inevitable success stories in retrospect.

Many of today’s emerging large-scale philanthropists aspire to similarly audacious successes. They don’t want to fund homeless shelters and food pantries; they want to end homelessness and hunger. Steady, linear progress isn’t enough; they demand disruptive, catalytic, systemic change—and in short order. Even as society grapples with important questions about today’s concentrations of wealth, many of the largest philanthropists feel the weight of responsibility that comes with their privilege. And the scale of their ambition, along with the wealth they are willing to give back to society, is breathtaking.

But a growing number of these donors privately express great frustration. Despite having written big checks for years, they aren’t seeing transformative successes for society: Think of philanthropic interventions to arrest climate change or improve U.S. public education, to cite just two examples. When faced with setbacks and public criticism, the best philanthropists reexamine their goals and approaches, including how they engage the communities they aspire to help in the decision-making process. But some retreat to seemingly safer donations to universities or art museums, while others withdraw from public giving altogether.

Donors don’t want to fund homeless shelters; they want to end homelessness.