I could be wrong, but I'm more concerned that Baker Mayfield may have finally figured out how to play in the NFL than I am with 36 year-old Kirk Cousins suddenly becoming a game changer. Cousins is a decent to good QB, but he's not a guy that makes his team better than the talent they have. He makes Atlanta relevant and puts them back in the mix in the South again, but I'm more concerned with Baker building on last year and getting better than Cousins turning Atlanta into a good team. At his age, he's likely to regress, not improve.
Then again, Carr could be better in a new offense that fits his skills better so it's hard to know who will end up the best QB in the South. They all have their individual strengths and weaknesses but they are all pretty close right now.