Right; so you're bothered by the fact that there are substitutions of x which make true the proposition ∃x:not(sells(Amazon, x)). These are counterexamples to their outrageously false marketing claim ∀x:sells(Amazon, x).

To what extent would you say this eating you alive?

(BTW: that marketing claim comes from the "Everything"; a collection which is "biggest" isn't necessarily exhaustive; just bigger than others.)