Political scientist here. The United States has tried relying on charities in the past. Here's (partially) why it didn't work out: people are selective to the charities they donate to and charities are often selective to the people they choose to help (some charities target war veterans, some children, some minorities, some certain neighborhoods). This leave a large, noticeable gap of many people left ignored. It's not a matter of whether people wanting to be taxed or wanting to give to charities; of course no one wants to be taxed. The government took the responsibility from the church and various charities because they weren't providing enough help across the board to citizens in need. I'm not saying don't donate to charity or volunteer, you should, but I am arguing that government, albeit in need of improvements, is one of the best mechanisms for helping the needy.