A very important reason missing from your list. Every transaction that occurs will be electronic and on the blockchain. That allows much easier monitoring of activity for multiple purposes, among the most important to a government is tax collection. Other purposes will vary and be dependent on the ethics and intentions of people within the governing agencies.

Note that most governments and banks have been moving towards “cashless” systems already. Use of blockchain based currency facilitates the transition that is already occurring.

The biggest question remaining is how current banks fit in this new paradigm for money.