As the BRICS attempt to leave the euro dollar system behind with their own project the dollar will decline in relevance.

There is no way Russia India and China will ever form a longstanding cohesive economic unit due to realpolitik

The third world has no incentive to replace the USD with whatever the BRICS cobble together ( meet the new boss same as the old boss.... )

The the Great Game is played on the third world because it has the raw materials. Previously this meant the winner of the game was able to dictate trade terms in the winners currency because there was no other option.

Now there is...Bitcoin. imagine Nigeria only accepts BTC for is hydro carbons.

Imagine Zimbabwe only accepts BTC for its agricultural products.

Imagine east Africa only accepts BTC from tourists.

The third world is going to force BTC on one of the power centres.