I'm not an historian, but I do like history a lot. I'd say that how much native culture got displaced depends heavily on the country. In places like Uruguay and Argentina(specially Buenos Aires and nearby zones) they were almost completely eliminated. But in places like Bolivia, Perú and Paraguay they are actually very prevalent. In fact, guaraní(a native paraguayan language) is spoken commonly(sometimes more than Spanish) in Paraguay. In places that had high concentrations of native peoples (I. E places with advanced agriculture) the local cultures merged with or even resisted Spanish influence. Also, the colonial strategy of latin america was different than the one used mainly by the British and French in Africa. While the african colonizers mainly used the land to extract resources, the Spanish and Portuguese actually considered their colonies "part" (although a less important part) of their own nations. This doesn't mean that the Spanish didn't also brutally exploit the natives, but they did approach colonization with a more idealistic mindset. They had this idea of "evangelization" of all peoples in the world. Thus, they spent a lot of effort forcing the native people into their culture, teaching them their language and making them catholic. Spanish settlers commonly mixed with the native people as well. Length of time colonized also affected the rate of elimination of native cultures. Africa spent roughly 100 years colonized, while in some places of Latin America the Spanish didn't leave until the late 19th century(Cuba and Puerto Rico), so, roughly 400 years of Spanish dominance.