08/07/23 Fascinating question. I don't see a BRICS currency even coming into existence anytime soon, much less becoming a world reserve currency.
BRICS is a talking shop. The three big economies in the group that really count -- China, India, and Brazil -- are also among the most closed and protected economies in the world. It's not easy to maintain trade barriers and to expand synergy at the same time. Russia and South Africa are much smaller economies, and will follow where the big dogs lead. Russia is totally occupied with losing an aggressive war of choice, and will be facing broad sanctions and possible war crimes trials for the foreseeable future; South Africa chronically balances on the brink of becoming a failed state. They'll be looking for support, not providing it. The big three will continue to talk a good game and then go their own ways.
Brazil is currently running a significant trade surplus with China. In the short term currency cooperation will be good for both, because paying Brazil in Reais and China in Renminbi will lessen their need for dollars or euros. But eventually Brazil may end up, thanks to the surpluses, with more unconvertible Renminbi on account than it can easily spend on imports from China, and China will run out of Reais. When and if that happens, Brazil's priority will probably become finding a way to shed that unconvertible Renminbi burden, not replace it with another unconvertible currency. And I agree with J.V.M76 with respect to Argentina and Venezuela. I read Lula's remarks as intended to lower temperatures and signal continental solidarity. Brazil's financial security is too precious and hard-won to risk on tying it to the region's basket cases, and Lula knows it.
I think that Lula communicated exactly the role he sees for BRICS by nominating his protegée and successor, Dilma Rousseff, as President of the BRICS Bank. Brazil has its share of distinguished economists, including Left wing economists, and if a currency union were his concern one of them would be in the job. Dilma's record on economic management is, to be charitable, uneven, but her access to Lula is unquestioned. She's at the BRICS bank to symbolize that Brazil values the organization and to ensure that a prestigious communications channel is in place, with the added benefit of getting her out of the country, where she continues to be a political liability.
As far as the Real is concerned, there's no doubt that it's been strong, particularly against the US Dollar, since the end of the pandemic. My problem is that I can't see why. Brazil's economic recovery has been positive, but it has also been halting and uneven. It doesn't measure up to the strength that the US economy has shown during the same period. There's a word for a runup of an asset value that doesn't seem to bear a relationship to underlying fundamentals: that word is "bubble". I'm only moving the money into Reais that I need to live on. until it's clear whether we're experiencing a bubble, or something more solid.