Weird fun fact (as an Argentinian who went to school in England for a few years): in English-speaking countries, America is not a continent in the same way as in Spanish. In English they have two continents: South America and North America.

So the word "American" in English does not mean the same as "Americano" in Spanish.

There's really no natural word in English to refer to someone from "El continente Americano", because no such continent exists in English. That's why they use the word "American" to refer to someone from USA exclusively.

"American" to refer to USA exclusively does make sense either way because USA shares the continent with at least two other countries no matter how you slice it.

You probably meant "doesn't make sense".

Correct

Frankly, the model with the single America continent doesn’t make any sense, because south and north Americas are so different in both geographical and cultural/historical sense.

Continents are about geology not culture

Well, North and South America are two different tectonic plates[1].

[1] https://www.usgs.gov/media/images/tectonic-plates-earth

They really aren't, there's no objective way to divide the world into exactly 7 continents (or 6) using geology.

America, Afro-Eurasia, Australia, Antarctica

I can count 4

If it is successful then the next region would be in the US