Here? Southern tip of South America is Patagonia.
As for the reasons, we have only speculation. Patagonia is pristine and the farmland is still nascent / fertile. In the event of the Samson option, the Andes and everything to its West should prove hospitable (or as hospitable as can be in the event of nuclear fallout).
Additionally, Argentina has not yet been looted by the THFCs unlike many European nations (Russia for example).
The United States is a collapsing empire whose riches are being stolen by the oligarchs. It will not be long before the financial system and economy fall off a cliff - Trump's true purpose is to facilitate this looting, hence his installation into the WH.
Milei's "free market" reforms were designed with the intent to attract international capital, so it should not be surprising to see Argentina continue to rise through the next 20-30 years before its apex and slow descent into chaos as the cycle dictates.