The poor areas of US cities are also much poorer though, and Latinos and Blacks are poorer than minorities in Canada (and more numerous) so maybe Asians partly just look good by comparison in the US.No idea how accurate or comparable those listed sources in the article are (in many cases the knowledge of English could be only having learned it a few years in school the way many Anglos in Canada learn a little French, or overestimates based on self-rated perceptions), but according to https://en.wikipedia.org/wiki/List_of_countries_by_English-speaking_population, China has only 5% who know English and India 12%, while Sri Lanka, Pakistan, Nigeria and Hong Kong are in the 40s and 50s % range of English speakers and Philipines in the 90s % (it was occupied and ruled by the US at one point after all).
West Indians who have been English-speaking for generations are native English speakers (with a local variant of English often being a creole but nonetheless no less a native tongue) while some of those other colonies might only have either English learning in school as a second language or cursory knowledge of it. But of course immigrants are not representative of the populace of the home country but often more educated.
So I would think you'd be right that Scarborough's higher Chinese population probably accounts for much of the trend. For some reason I'd had thought Hong Kongers made up most of the Chinese in Scarborough (maybe that's an outdated view based on what it was like in the 90s).
Also I notice that Asian Torontonians' socio-economic demographics differ compared to the stereotype south of the border. In the US, you hear about this thing where Asian Americans are assumed to be wealthy and get called a "model minority" but I don't think that's as much of a thing here. In US cities, you would not often have the "Asian" part of town be a poor area.
And the US doesn't have many areas that are predominantly Asian outside of NYC, LA and the Bay Area.
Examples of Asian parts of US cities that are at least somewhat poor would be Elmhurst and Flushing in Queens; Sunset Park, and to a lesser extent areas south of there in Brooklyn; Journal Square in Jersey City; Chinatown in Manhattan; southern Sacramento - sort of, it is the poorest part of town and the most Asian, but Asians aren't dominant, but still about 30-40% and more numerous than anywhere else in Sacramento; Koreatown in LA; SW Seattle. The Asian enclaves in suburban LA, suburban NJ and Sugar Land, TX are more middle class to upper middle class. The Bay Area seems to have a mix but probably skewing more middle to upper middle class.
And while Toronto does have low income Asian enclaves, other Asian enclaves like northern Markham and adjacent parts of Richmond Hill, and parts of Mississauga, are much more middle income.
BTW I'm surprised there's such a big difference between India and Sri Lanka/Pakistan. I also didn't expect Filipinos to speak English in such large number since they do after all have their own languages just like India.