The issue with the argument that GA is unable to flip before 2025 is that it ignores how rapidly the state is shifting in the Democrats' direction. The swing from 2016 to 2018 itself should be a huge warning sign for Republicans especially when Georgia was more R-leaning in 2018 than in 2016 (just some evidence that Georgia is not a state that is affected by the national environment). Democrats can easily make up the 1 point deficit that Abrams lost by, particularly in the presidential race.
I can still see Perdue outperforming Kemp unless the national electorate ends up being like >150 million voters.
Given the polling showing such high enthusiasm for next year's election (enthusiasm already in the 70s!), it wouldn't surprise me one bit if we ended up reaching that magic number of 150 million.