I agree with your assessment.
I am not US American though. I live in America (Canada specifically) but I was born and raised in Europe. I'm afraid the cynicism in my original comment requires this context to be received.
In my opinion it seems to reflect an expectation in culture in general. Most movies filmed in Canada do not actually depict Canada. I lived in Toronto for a while where there are almost as many NYPD cruisers as there are TPS cruisers and as many Yellow Cabs as there are Beck Taxis. International YouTubers translating things into Imperial Units and US Dollars in videos is another often seen accommodation to this.
I think my simplest heuristic for agreeing with your point is how much content there is in the English Wikipedia vs. other languages. I haven't run the numbers, but I'm sure it's also much more US centric (take a look at the # of articles on the US government (current and historical) vs., say, the Brazilian government...)
America just tends to be particularly prolific in producing online content. No, I'm not claiming this as a statistical fact, but I am claiming that's the impression day in an day out so might as well assume as much...
In my opinion it seems to reflect an expectation in culture in general. Most movies filmed in Canada do not actually depict Canada. I lived in Toronto for a while where there are almost as many NYPD cruisers as there are TPS cruisers and as many Yellow Cabs as there are Beck Taxis. International YouTubers translating things into Imperial Units and US Dollars in videos is another often seen accommodation to this.