The government is inefficient (which I agree with),
but charities somehow magically aren't?
Not to mention now nobody is obligated to pay into them,
You answered it yourself. Poorly performing charities will lose donators and disappear. Poorly performing governments will continue to take your taxes whether you like it or not (frequently using the poor performance as the reason for doing so).
You are assuming most people pay as much attention as you do. Most people donate to the charity they see on TV the most. They don't give a shit about said charity's efficiency, they just want to say, "Oh, I got this pretty pink ribbon, see how great I am!"