Do I really need to explain this stuff?
You think that city = country? So a problem of a particular city should be solved on the governmen level? BS. Your comparison is weak. Each city should have their own small government for dealing with such problems but there is no need for a one giant government.
City problems are dealt with by
local governments. We elect city officials, like the mayor, or the dog catcher.We can even elect our Sheriff, if we live in the sticks. What we do not elect is our war chief, to defend us from the frickin' commies over in the next county, or from the vicious tacos from 'cross the border. That's what the feds are for.
Read books, bro.