Why does the US consider everything south of it its “backyard” and not Canada? I promise you the average American doesn’t think of some white German descendent when you talk about South America unless it’s Argentina

Doesn’t matter, that’s not what people in America or Europe think and they don’t consider them in the club. The “collective west” and the “global north” and the “first world” are racist clubs filled with white people and nobody in those groups consider Latin America part of it

Are you being some kind of weird nazi pick-me, or are you just severely misinformed?

The average person in Mexico, Central America, Colombia, Ecuador, Venezuela, Peru, Chile, Bolivia, and like 75% of Brazil just doesn't pass as a white person here in the US.

that's like 90% of Latin America or 75% of South America. They're not white, they're admixed with Europeans. Just like Black Americans are.
I know a lot of you think you're white because you're lighter skinned than black people. Arabs and lighter skinned Indians also think that a lot of the time. They're not. Almost everyone in Northern Europe and Anglo America can tell the difference

and tbh even Argentinians don't really look that white to me on average.

Also, South America is FAR poorer than Croatia. Latter is $17k GDP per head. Average South American GDP is $10k according to stats, but these don't weight for population so small rich countries like Chile and Uruguay make it falsely larger. South America is dominated by Brazil whose GDP is $7k per head, so yea Latin American avg GDP/capita is something like $9,000 if we're being very optimistic.

And like somebody already said, Croatia itself is the periphery of the west

Look, neither you or I get to define what "the West" means. It is a racist concept, but that's the unfortunate reality of the situation. "The West" is not defined by who thinks they should belong to it, it's defined by the material reality of exploitation. It's nearly synonymous with "Imperial Core." If you're in the periphery, you are not part of "The West" no matter how much your society mirrors so-called western culture. Just as a regular worker is not part of the bourgeoisie no matter how much they want to be. There are the exploiters and the exploited. Latam, on the global stage, is exploited by the imperial core and there is no escaping that fact. The exploiters will never see it as part of their club because they're exploiting it! It's not like we (hexbears or leftists in general) see this as a good thing or want to perpetuate it. We want to tear it the fuck down. But we can't deny material reality, and it seems like that's what you're trying to do by insisting that Latam is western and getting mad at us for the fact that it's largely racism that determines who belongs to the in-group "Western" and who doesn't.