The reason bankers and the wealthy are throwing mountains of capital and political leverage behind mass adoption of cashless societies is the greater control it offers. If they illegalize cash and paper money. Then they have complete control over monetary transactions.
I think it's also governments who are heading off currency liquidity risks. Everyone is becoming increasingly worried about the next financial crisis and its effects on liquidity. When depositor money is locked inside the banking system (as opposed to cash), it's easier to prevent shocks to the economy. There are no bank runs in a cashless society.
Its banks and regulated finance that is usually the biggest offender in regard to liquidity risks. It never takes banks long to move in and offer capital support to countries like russia, drug cartels and terrorist groups after the US passes economic sanctions against them. The type of news story posted below is common for the banking industry.
Long before bitcoin or digital currencies existed, it was common for many to criticize the government and banks for "creating money out of thin air". That is the original source for that trope which today is almost universally made exclusively against bitcoin and digital forms of money.
Banks and governments might be said to represent the biggest liquidity risks across the board in terms of them doing business with groups and demographics under sanctions, expanding balance sheets and money supply without proper oversight or accountability and greatly exceeding what might be described as safe levels of debt in terms of state deficits which are commonly measured in trillions.