The RBI has started trials of its retail Central Bank Digital Currency - or digital rupee - in 4 big Indian cities. The RBI has chosen 4 banks, SBI, ICICI, Yes Bank and IDFC for the pilot, and these banks have chosen some individuals and some merchants who are account holders, for this. But... why would anyone take the trouble to create a separate e-wallet when most of us already have UPI? Well, there may just be some reasons. Latha Venkatesh explains!