2. Atlanta can offer Kirk the best chance to win
From the perspective of Kirk Cousins what other team in the league can offer you better weapons and a chance to win? You're joining a bad division on a team with an improving defense and great young weapons.
It would be fair to assume that Cousins prefers to stay in the NFC and stay away from the stacked AFC. If you're Cousins unless the contract is obscene there is no reason to join the conference with Joe Burrow, Josh Allen, Patrick Mahomes, Trevor Lawrence, Lamar Jackson, and an emerging C.J. Stroud.
Kirk staying in the NFC makes the most sense and looking at the QB needy teams that could look to free agency only Atlanta can offer great young weapons. While Atlanta may not have Justin Jefferson they have far better depth when it comes to their weapons.
Bijan Robinson, Kyle Pitts, Drake London, Jonnu Smith, and Tyler Allgeier are a great group to offer a veteran quarterback. Add another receiver in the draft or free agency and this offense is perfectly set up for Kirk to come in and play at a high level from week one.