O stop Booker! You know it's 'cause all the citizens are Wood Elves!
You don't see anyone walking about during a flyover because Atlanta has the densest urban forest canopy of any city in North America, equivalent to Seattle WA, but wayyyyy larger. Atlanta has, also, the largest city limits - city council boundaries, to you Brits - that is Not a merged county/city (such as Miami Dade, FL) in the country.
airline flight approach preview; note several cluster business districts....and shit loads of trees
Buckhead, the Northern Business District;
An Industrial Park just west of that....full of trees...and wood elves!
Five Points (central business district/downtown) and all the freakin' trees just behind there?
And of course, Piedmont Park in Midtown the middle business district...designed by Frederick Law Olmstead, who also designed Central Park in New York.