Some dream that these are steps to gradually get rid of the dollar and establish new financial rules for the global market, but this is closer to an illusion. Simply put, even the countries in the BRICS alliance cannot stop using the dollar because they cannot completely isolate themselves from the global market. In addition, the largest creditor to the United States is China (a founding member of BRICS), and most of these debts are in the form of government bonds denominated in dollars. If something happens to the dollar, everyone will be affected.
Every country wants to find themselves where they would have a stake, and not just continuing being floor members in the global arena and that's why they all continue to pursue their different interests with every possible opportunity they can lay their hands on. I do believe in competition because that's what makes for standards to exist, particularly healthy competition. So in my opinion, the BRICS coming into existence shouldn't be seen by the Western or European countries as a platform that wasn't supposed to exist except they no more believe in the gospel of the freedom of association as preachers that they are.
The US dollar is the king of all currencies globally because it has the most wide usage in international transactions than any currency we can think of and for now the BRICS doesn't come close, so it's not surprising that some of the BRICS countries still make do of the dollar despite their BRICS alliance. It's not anything they can do away with instantly as there are certain economic battles they must over come before they can have that accomplished but this could take years to happen or perhaps the BRICS could as well die a natural death if it fails to achieve it's aims.