Question

Why sdr failed to become reserve currency of world?

Answer 1

The SDRs (special drawing rights) were born with big ambitions. Created in 1969 by the IMF to support the Bretton Woods fixed exchange system the initial expectations were that it would become a major component of global reserves, while gold and reserve currencies were regarded to have only a minor incremental role in official reserves. 

this is the reason of SDR to fail in becoming reserved currency of world

Answer 2

When the euro debuted on the world financial stage, many economic analysts touted it, over-optimistically as it turns out, as the world's next reserve currency. The prediction was reasonable enough, based on the notion the combined financial strength of virtually the whole of western Europe might be a powerful enough economic force to topple the U.S. dollar from its position as the world's reserve currency. The euro fairly quickly became the second most important currency in the world, but as of 2015, it has failed to supplant the U.S. dollar at the top of the world's monetary heap. There are several reasons for this including liquidity, financial stability of the European Union, sovereign debt problems, the financial crisis of 2008 and the rapid rise to prominence of the Chinese yuan.