I think people think South America is a great example of race relations or something, of course everyone but people of significant African descent is saying this.
As a black man I would rather be in the Uk than many of these places, one poster said Uruguay is hugely influenced by African culture as if that even matters, so is US and so is the UK.
I wouldn't disagree with you on that.
There is massive inequality, it is structural and some sectors of the population are more affected by it. Speaking about Uruguay specifically, you are not going to see too many "successful"* black people.
I don't think racism is the fundamental problem though, let alone linguistics. It's anchored in how the population has evolved as a result of different "waves" of migration from various nationalities. Those national collectives tended to "support their own", it has feck all to do with skin colour, but Italians helping Italians, Basques, Jews, Catalans, Galicians, Poles, Turks, Armenians... and so on. It was primarily British immigrants that came out of their own free will in the second half of the 19th Century (to pretty much set up all the infrastructure businesses), the rest usually fled war, poverty or persecution.
Those collectives always had the power of a shared experience, a shared origin, business and diplomatic links for trade with their countries, they got organised around that with support from their homeland... E.g. you will find a British school, an Irish school, a German school, a French school, a Hebrew school.
For obvious reasons, you are never going to find an African school, or significant and effective external community-building support. It's not a level playing field but it's not you are being discriminated against, nor has it been deliberately designed to be so, but it's much harder, no doubt about that.
Not sure a football blog post is the place to delve into all that anyhow.
*i.e. leave out footballers, artists, and any other purely talent-based success.