I volunteer for a charity where each and every $500 donation supports a kid going through a program. That program regularly changes kids' life trajectories in a way that has a difficult to quantify multiplier effect throughout the community.

I am highly skeptical of wisdom of utilitarianism in charitable giving. No one has non-toy models so the math is all made up nonsense. More importantly, proximity between the giver and the recipient has profound agency effects that are completely ignored by most utilitarians. You tend to get better outcomes when you allow agents to center their personal projects, even if resources aren't optimally allocated when ignoring this "agent centering effect".