the Brics are a strong force that will rival the u.s and it's allies
I like to think of BRICS the way I think of Bitcoin. Just as Bitcoin is not "rival" of anything and is just an alternative to existing payment systems trying to offer system that doesn't have the same flaws; BRICS is also not exactly a rival to anything. It is an alternative alliance of countries to solve various problems including economical because the existing system (eg. UN, IMF, etc.) wasn't working as it should have been working.
It may sound bad, but US President Donald Trump has stopped the progress of BRICS. He thought that such an alliance might hurt US interests and undermine the dominance of the dollar. Successful businessmen like Trump and his prudent decisions have thrown the BRICS countries into confusion. Trump has basically watered down the kind of prudence that the countries showed to emerge as an alliance of emerging economies in the world. He has ordered the executive to impose higher tariffs on those countries that try to introduce an alternative currency other than the US dollar.
Among the BRICS countries, Russia and China are a challenge to the US economy, and Trump understands this well and considers the formation of economic or cooperative groups with those countries to be against US interests. The IMF and the UN are the shadows of US.