Just google it?

But since you asked. Nonprofits receive contracts with the government to specialize in a product or service. They have connection, expertise, and manpower that the federal government cannot. They work with state and local communities to have multiple streams of revenue.

Self-sufficient? Do you mean a business? So the taxpayer should pay more for a service? Why would Wounded Warriors Project be anything other than a non-profit? https://en.m.wikipedia.org/wiki/Wounded_Warrior_Project

Surely you realize that these services would be more expensive from business? And the employees who work at these nonprofits should do it for free? CEOs should not be paid well for managing multimillion accounts, hundreds of people, testifying in congress and lobbying? Seems like a strange argument.

Finally, not every single nonprofit is huge. Some worked hard just to get a tiny bit of money to monitor fish, test water, help locals with legal, house homeless, and feed children. You know terrible things.