You underestimate the importance of national prestige in South America. True the Brazilian Naval air force is at a low ebb right now, but that is simply a funding issue. Once that has been resolved overhauling the rest of the Skyhawk fleet to make it operational again won't be too difficult, and the pilot issue will resolve itself once the aircraft are flying again. Pilots are probably still being trained in the US at this time, to maintain their currency. Argentina hasn't had an operational carrier since the late 80s, yet has carrier qualified pilots and sqns still.
The need for a prestigious and capable navy for Brazil (and indeed other South American countries) is not about attacking their neighbours. They want to be seen as 'players' on the world stage, in the UN especially. UN operations are where they want to be, to be seen to be participants, like 'first world' nations and not in need of rescue like 'third world' nations. Helicother carriers would not give them the same prestige as a strike carrier, even if they were more useful in a joint UN type operation. I think in the next decade Brazil may well move towards adding a large deck amphib such as a variant of the French Mistral class to their fleet in addition to Sao Paolo. The Brazilian Navy has spent decades trying to acquire CVA capability. I see no prospect of them giving it up any time soon.
