That’s part of it. The other part, like a lot of things in Georgia, is politics.

https://cviog.uga.edu/news/061319-counties.html

From the article, “Until 1962, Georgia used the County Unit System to choose many elected officials. The system gave more political muscle to urban counties, so it benefited rural Georgia to create more counties and therefore more muscle.

“Another rural county, that’s two more rural votes there, off-set those interests in Atlanta,” Charles Bullock, Political Science Professor at the University of Georgia explained.

In 1945, the Georgia Constitution capped the number of counties at 159.”