Brady isn't showing signs of physical decline yet, but he needs to improve his playoff performances as of late. He is still living off the three rings, which buys him A LOT of currency (understandably so), but like I've pointed out, the last several games have been uneven and not great overall.
BB needs to bring in a defensive coordinator and let him run the show. Patricia is a puppethead. BBs Ds haven't gotten in done in a long time. I don't have confidence in him putting together a top-tier defense anymore, and the Pats need one, because after this postseason, I can't count on the offense to carry the Patriots to carry the team to wins like I can in the regular season. They need a new perspective to make this happen.
But they do have the personnel to keep status quo for a while (make the playoffs, possibly win a game or two before bowing out). A lot of other teams' fans would take what the Patriots have done over the past several seasons (a 16-0 season, two Super Bowl appearances, three AFC title games, and constant relevance), but like the Yankees of the 2000s, or the Braves of the 90s and beyond, when the prosperity doesn't result in titles, or not nearly enough of them, there's no shortage of fans from other teams waiting to let you hear about it.
I don't know if its Brady, or the fact that smart defenesive coordinators (typically in the playoffs) can take away his comfort zone.
I think it calls on the OC to make the half time adjustments, or prepare better agains the better Defenses. Brady' is already asked to win the game himself for the most part.
On the defensive side, I don't think BB has the horses, or has developed the horses to ride deep in the playoffs.
Since Seymour was traded, you have had no dominant pass rusher, which every Superbowl team needs to win.
Your linebacking corp is not as talented as when you had Teddy Bruschi and Mike Vrabel.
And you also haven't had the intimidating secondary without Ty Law and Rodney Harrison
You had a core that is gone on the Defensive side. It is still rebuiliding but you just don't have those dominant players anymore, that BB had the luxury of having to win his championships.