How is it useless? It's no more useless than the QUAD, SEATO, AUKUS.
BRICS - Brazil, Russia, India, China, South Africa simply an acronym coined by a Goldman Sachs economist to refer to the macroeconomic influence of those countries either unilaterally or in unison
But there are no formal alliances or treaties between all 5 members as a unified group that ratifies the acronym, either economically, geopolitically or military/security wise. The BRICS acronym is generally used purely on macro economic matters, and even then, sometimes the policies between BRICS members can compete with each other just as much as they may cooperate.
This is the major difference between BRICS vs AUKUS/QUAD/etc