I offered a thought experiment, and using the example of "giving $1,000" is easier to think about than "not taking $1,000". As a thought experiment they are equivalent, with respect to the question: who utilizes resources most efficiently?

By introducing variability of how much the government takes total it adds another question that is being used to persistently distract from the question of progressivity. When people say "the wealthy should bear a larger portion of the burden" a typical response is "we should be spending less on government!" – which is no response at all, just a distraction.

You said: "The notion that taxation should be predicated on whether the government or the person can 'better use' the person's money is damn scary." – which is EXACTLY what I was pointedly NOT asking. The degree of progressivity in a system does not determine whether a person or the government has the person's money, but WHICH people have how much money.