It really isn’t. It literally sits on top of the city of Atlanta with only doraville, tucker, and Stone Mountain as a buffer. Wether I’m in norcross , Lilburn, or Snellville I can get downtown within 15 minutes if it’s not rush hour. During my childhood, at least the parts that I was in metro Atlanta, I’ve lived in Decatur, Atlanta, Stone Mountain, tucker, and parts of Gwinnett. Gwinnett, like dekalb, and Clayton are also part of Atlanta’s logistics backbone. It also used to provide/city of Atlanta’s water. I can understand counties like rockdale, Cherokee, Forsyth, Douglass, Henry not being included in the immediate metro area.