Why is the county of Staten Island Richmond why not it be kings county?

Staten Island is officially designated as Richmond County due to historical reasons dating back to the consolidation of New York City in 1898. The name "Richmond" honors the early colonial settlement and the county's original designation. Kings County refers specifically to Brooklyn, which is a separate borough. Thus, while Staten Island is geographically part of New York City, its governmental structure and historical naming conventions distinguish it as Richmond County.