Iguazú Falls may be great but it was there long before Argentina was there. I think you nailed it: when was Argentina great? By objective standards - never. In fact the Singapore/Argentina comparison is often used to demonstrate how being rich in natural resources no longer necessarily means a country will be prosperous. When you’re the poster child for economic underperformance…
When was Argentina great - in the opinion of Argentina’s old people? Back in their day of course!