A pertinent post full of pertinent questions.

'Recently, there has been a global movement toward eliminating cash.'
Strictly cash cannot be eliminated when cash is apprehended at its functions.
Cash as Unit of measure, Unit of exchange, is necessary for the very function of human society, thus what the movement may leads to is a change in the perception of cash where cash can have another form but not being eliminated.

The concept of 'fine adjustment' (réglage fin) is the tool use in dealing with liquidity in the course of open market.