Centralizing powers to the federal government rather than the states can be in the interest of the country for several reasons. Firstly, if each state established its own army or militia, it could lead to internal conflicts, lack of coordination, and potential security vulnerabilities. A unified federal military ensures better defense and protection of national interests. Secondly, having each state with its own currency could lead to economic chaos, reduced interstate trade, and difficulties in implementing consistent fiscal policies. A single national currency managed by the federal government promotes economic stability, facilitates commerce, and fosters a stronger, integrated economy. Overall, centralizing these responsibilities to the federal level ensures national unity, security, and economic cohesion, promoting the well-being of the entire country.
I hope this helped!
~~~Harsha~~~