The reason more boroughs don't exist in the United States is that they complicate city governance to have multiple, overlapping authorities. The reason they exist in New York City is that each borough in the city is also its own county.
BOROUGH COUNTY
Manhattan New York
Queens Queens
Brooklyn Kings
Bronx Bronx
Staten Island Richmond
So the New York boroughs are different from boroughs in other cities in the US or other countries. The few states that use the term generally use them as a means to distinguish one form of municipality from another (townships, villages, towns, cities), as opposed to a sub-unit within an existing municipality.
In the US, the charters of cities are determined by the state government. So to get more boroughs, you need the state government to want to create such an administrative entity. You need to think what advantages they would give because you are going to need to give state legislators a reason to add another layer of government.