To your credit you did establish benchmarks.
As for these former Crown Colonies; Bermuda has a population around 65,000 and the Bahamas about 380,000; all imported from Africa. Not nitpicking, but are these really nation states???
Botswana is 75% desert, suffers chronic drought and is land locked. Successful???
Gabon? Probably yet poverty is endemic.
As for SA, disagree w/Chile and disagree emphatically w/Argentina and Uruguay. The bane of all three has been their impulse toward dictatorial rule; a condition that chronically resurrects itself throughout SA history.
In one of the ironies of history, Argentina was the 4th wealthiest nation on earth on the eve of the Great War due to its massive gold stock, as well as its thriving cattle, coal and wheat exports. But a succession of military strong men, such as Juan Peron, drove them into the economic ditch from which they have yet to recover.
As for Uruguay, I'll just post from Wikipedia (not always accurate, but a good summation paragraph):
Uruguay is ranked first in Latin America in democracy, peace, lack of corruption, e-government, and is first in South America when it comes to press freedom, size of the middle class and prosperity. On a per-capita basis, Uruguay contributes more troops to United Nations peace-keeping missions than any other country. It ranks second in the region on economic freedom, income equality, per-capita income and inflows of FDI. Uruguay is the third-best country on the continent in terms of HDI, GDP growth, innovation and infrastructure. It is regarded as a high-income country (top group) by the UN. Uruguay is also the third-best ranked in the world in e-Participation. Uruguay is an important global exporter of combed wool, rice, soybeans, frozen beef, malt and milk.
It formed a new Constitution in 1984, meaning it has had a free, stable and democratic form of government for 30 years. That's a good run, so far, and if it can avoid any totalitarianism, it will continue to develop and advance.
Dictators are the bane of South America, but if this current era of them would die off, maybe the internet will prevent the takeover of media that seems to proceed a regime uprising in that part of the world.