I do think your points are valid, though I think part of the reason for Americans mostly viewing everything in American context comes down to the size of the U.S. The country is so big and there is even a bit of diversity of culture in different regions. Each U.S. state was (debatablely) originally meant to act as its own nation, with the federal government being something more akin to the EU.
The analogy isn’t perfect, but what I am getting to something here. Though I have never been to Europe, I do understand that there is a larger breadth of culture, largely a product of much more long standing civilization and history, most of which developed centuries ago when long distance travel was less easy. In the modern era, it is more common to travel in between countries and even speak multiple languages, making it much more obvious how diverse the cultures of the world can be.
Coming back to America, it is a settler colonial nation that is much younger in scope, so the culture is a bit more hegemonic but far larger in scope. All that is to say, an American who lives in New York could travel to Florida (roughly 1100 miles), and the culture would be a bit different, but no where’s near the equivalent travel of, say, a trip from Poland to Italy.
Again, I want to be clear, this is not a defense, just an explanation of part of the reason you see such American centric discussion. For many Americans, even if they have traveled, they very well may have largely only ever experienced the greater American sphere of culture.
Also gave us the first female president