The big push for going cashless is driven in part by the need to impose negative interest rates. The bankers know they can't do so without people fleeing to cash, and "hoarding" (saving).
So they lobby hard to get other changes, so that larger denominations are retired, eventually culminating in the complete restriction of using cash at all.
Once your citizens are trapped in the banking system, then negative rates can be a reality, legally stealing from savers to "stimulate" economic activity.
What they didn't count on, of course, was the advent of cryptocurrencies which completely blows a big hole through the bulkhead of cashless sovereign control.