The Braves losing Sonny Gray to the Cardinals was not ideal
Basically everyone thought that the Braves and Sonny Gray were the perfect pairing of a free agent and a team at the start of the offseason. Atlanta has generally avoided long-term deals, especially with pitchers. Gray was coming off a Cy Young caliber season AND was thought to only need a two or three year deal this offseason. In terms of fit, there wasn't a better option on the free agent market.
Unfortunately, Gray did not end up with Atlanta and instead the Cardinals worked their devil magic and signed Gray to a three year, $75 million deal. There is no denying that St. Louis needed at least one quality arm for their rotation given the combination of senior citizens and Island of Misfit Toys residents that they ran out there in their rotation in 2023, but the Braves losing a key free agent target to a team that finished dead last in the NL Central last season sure doesn't feel great.
As for Gray, this did feel a bit like him going with his personal preference with the Cardinals. He apparently entered the offseason wanting to sign with the Cardinals and they are reasonably close to where he lives in the offseason. For a guy who is likely heading into the final stages of his career, comfort level and preference is going to carry a lot of weight.
Still, now the Braves have to contend with a Cardinals team in the National League that does look somewhat improved on the pitching side and has some dangerous hitters in their lineup. Plus, St. Louis seems like they always find a way to be an annoyance to the Braves and this offseason was clearly no different.