The government has discontinued with a certain denomination of currency notes because there are too many fake notes in that denomination,but it has to be replaced with another denomination
Digital wallets can be used even by loading cash without linking it to a bank account that way its unaccounted money,I can give someone cash and they will load it to my wallet,you create a YOUGOV account complete surveys and they will load it to a digital wallet PAYTM in India that is unaccounted when you pay taxes it is not traced so the system is still very primitive people could have hundreds of thousands in a wallet without being linked to a bank account
Went to Goa last year no one uses digital wallets there people prefer cash I used my credit card or withdrew cash form a ATM,even the place where I stayed I paid 80% cash balance 20% credit card
Recently I bought a 4K smart TV 65 inch paid full cash