What's easier making a policy that 20,000 banks have to abide by. Or creating a new digital currency that 20,000 banks AND every business has to figure out how

What's easier making a policy that 20,000 banks have to abide by. Or creating a new digital currency that 20,000 banks AND every business has to figure out how to accept? You hand waved away "creating an app", but that app has development and design decisions that need to last, needs to get adopted by people, and needs to be accepted. A free banking policy is significantly easier and would cost the government less.