What AOC actually said was (linked in the essay): "You can’t earn a billion dollars. You just can’t earn that." That is a strong claim - a claim of universal impossibility - but it's the claim she chose to make. Because she made a universal claim, an N=1 anecdote is enough to disprove it by counterexample.
Fwiw I agree that the universal impossibility statement is too strong.
But his example doesn’t demonstrate anyone earning $1b. It just demonstrates a very high growth rate at $1-2m.