Ah so it’s not about your desire to call yourself an American as much as that it bothers you that the USA is a hegemon and gets to dictate to a large degree how things are spoken of and referred to?
But, ask yourself this then: what else would they refer to themselves as? Unitedians? Statesians? US-Americans (you absolutely know people will still be annoyed that the word America is in it, and anyway - everyone would still end up just saying ‘American’).
I personally think the whole arguement is sort of hilarious because you and many other non Statesians think it’s not fair that you can’t call yourself American because you live on the American continent. Meanwhile, every Statesian I have met prefers to refer to themselves by the state they’re from rather than call themselves an American.