The G7-BRICS comparison has become the defining frame for understanding the global economic power shift. By one measure (PPP GDP share), the shift has already occurred: BRICS+ generates a larger share of global output than the G7. By another measure (nominal GDP), the G7 still leads. By yet another (per-capita income), the gap remains enormous. Which measure matters depends on what question you're asking.
For geopolitical influence, PPP GDP is more relevant because it measures actual productive capacity: how many goods and services an economy can produce. An Indian factory that costs half as much to build as an American one, but produces the same output, contributes equally in PPP terms but half as much in nominal terms. This is why China's military buildup has been so rapid despite a nominal GDP below the US: defense goods are produced at Chinese, not American, price levels.
For financial market power, nominal GDP matters more. The dollar's dominance in trade invoicing, reserve holdings, and capital markets means US financial influence vastly exceeds its GDP share. American stock markets are worth more than all other markets combined. The Federal Reserve's interest rate decisions affect borrowing costs worldwide. No BRICS institution comes close to this reach.
The technology dimension increasingly separates the blocs. The G7 (primarily the US) leads overwhelmingly in AI, semiconductor design, cloud computing, biotech, and pharmaceutical innovation. BRICS countries (primarily China) lead in manufacturing scale, electric vehicles, solar panels, and 5G infrastructure deployment. The competition is less about overall size and more about which domains drive future productivity growth.