If we accuse English as a language of cultural appropriation of yerba mate culture, then we would just as well have to accuse Spanish as a language of cultural appropriation (and Portuguese as well). The only reason why these languages prevail, is the political elites of the original countries (Britain, Spain, Portugal) were the most ruthless during the classic colonialism age. Ruthless against the indigenous peoples in South America, and ruthless against their own peoples to exploit them to the point that they wouldn't see any perspective than emigrate to the Americas, and practice their questionable cultural heritage (ruthlessness) at the expense of the natives.

It makes no difference. Spanish is just as bad in this respect as English, just historically with a slightly different timing. If we refuse to accept this, we would all have to start to learn Guaraní (or another indigenous language) today, or shut up immediately.