You’re proving my point exactly: those characterizations, especially in the context of Latin American culture as a foil, reveal their own biases. Both are based on anecdotes and vibes, not reality. To me, it's all narcissism of minor differences. I find the need to paint whole cultures with such a broad brush weird, especially based on my experience with people from around the world: most people aren't so different.
I think most are thinking about a higher proportion of adults living at the same household as their parents in some countries when they say that. However in recent year the proportion in the US got a lot closer to Latin American countries. Then again it probably significantly varies by race, ethnic background etc. which doesn't invalidate the anecdotal evidence people might have.
> cultures with such a broad brush weird, especially
US is very heterogeneous but it works reasonably well in many other places besides a handful of outliers.