By the way, one thing I always wondered? Are Canadians annoyed by that usage, or more or less accepted that they're not "American" in English? (I would especially appreciate if a Canadian shared their thoughts about this)
My two cents is US people are the ones who have an unusual take on the word "America". Outside the US, it's not very idiomatic to call the country "America", or even "USA". "US" is more common (and in both Spanish and Portuguese, it's almost always called "Estados Unidos").
The term "american" is mainstream both in Canada and elsewhere. I imagine that's probably at least partly a function of "unitedstatesman" being too much of a mouthful. (BTW, if you think that's a ridiculous word, in portuguese "estadounidense" is an actual word, albeit with a connotation of being something a "woke" person might say).
