The point of RCV isn’t to ensure your chosen candidate wins; it’s to ensure that whoever does win has at least some amount of approval from the majority of voters.
It does still have flaws, but it’s still far superior to the current system the US uses.
Thing is, this isn’t a “gotcha” to them. Their default assumption is “American = more qualified than anyone else” because they’re goddamn ignorant racists.
No one who is not American will ever be qualified in their eyes.