The govt is bigger and so it's harder and takes longer for them to convert to a blockchain currency but there doesn't seem to be a reason it can't be done.
The value of the currency using blockchain varies. Making your own blockchain-based currency is free or little in cost. Some cryptocurrencies are worth more than others. The currency you decide to trade in is up to you, though.
Some interesting banking related rules: Canada employs jubilee years on debt: https://globalnews.ca/news/3477636/debt-limits-death/
People on both sides blame the repealing of Glas Steagal during Clinton's presidency for the state of the stock market, and resulting misuse of money lead to the 2008 recession.