Depends on what you mean by "performing worse." Argentina has consistently had the second largest economy on the continent, third in Latin America, and ranks second highest in the latest Human Development Index Ranking. It also In other words, even while performing poorly, it's still doing considerably better than most of its neighbors.
No twisting invlolved, it's in the World Bank and UN data. But that's not going to stop people from shouting that Argentina is the next Somalia.
Not sure UNDP HDI rankings paint a clear picture of Argentinas
performance or contemporary merit in comparison to its neighbours, nor its trajectory.
According to these rankings, Chile scores 0.847 (inequality 0.67/ socio-economic sustainability 70.3) while Argentina scores 0.83 (inequality 0.71 /
socio-economic sustainability 65.8).
By comparison Venezuela is 0.726 (inequality 0.6/ socio-economic sustainability 42.3) while Peru is 0.759 (inequality 0.61/ socio-economic sustainability 82.8) and Colombia is 0.76 (inequality 0.58 / socio-economic sustainability 58.1).
Both of the latter are on the upward trend while starting from positions of
significant disadvantage in the 20th century.
Argentina however comes from a position of enormous privilege and wealth having a pre-existing and educated middle class - which is a changing / declining dynamic that is increasingly difficult to sustain. It is not a result of policies today or the recent past nor reason to be complacent and think that Argentina (or any country for that matter) is an unsinkable ship.
For me, the litmus test is to ask where you would have a better chance at a better future if you were poor - Argentina or one of its neighbours? And a "stable" currency
and access to capital have an enormous part to play in that test, but over the past decades Argentina has proved incapable of providing or sustaining these tools meaning most of what we see is just the remnants of "old money" and little else.