When you think of the Patriots dynstay you think of Belichick, Brady, and Kraft. Even with all the winning there can be frustration at times. It all started in 2014, when Belichick drafted Garoppolo and brought up Brady's age and contract situation. That didn't sit well with Brady, but he ended up winning two Super Bowls anyway. Then was the reason they traded Garoppolo to the 49ERS.
After Garoppolo was traded Brady thought Belichick not Kraft would commit to him and give him a two year contract. However, Belichick treated Brady like everyone else, like he wasn't bigger than the team. Brady put the winning and loyalty on the field and didn't feel the appreciation in return by Belichick. They respect each other no doubt, but when it comes to their ego its all about themselves.
Kraft didn't want to get in the middle and he should've as the owner
Kraft wanted to stay out of Belichick's decision on whether or not to keep Brady. Belichick wanted to go year to year, Brady didn't, and there was no deal. Brady wanted a commitment of two years, which Belichick didn't want to do with a 43 year old quarterback. So his ego and Brady's got in the way, which is why Brady is now a Buccaneer. Brady got the two year commitment from a different team, which he's been wanting from Belichick for years. Last time I checked Belichick doesn’t own the team, Kraft does. If Kraft wanted Brady so bad then fire Belichick and make Brady your quarterback. But he didn't do that because he knows Belichick is a football genius and will do what's best for the future of the team. Brady wanted final say as to when he would be finished playing, he didn't want that coming from Belichick.
Overall both of their egos got in the way at the end. As for Robert Kraft he didn't want to get involved even though he owns the team and not Belichick. It's sad to see it end this way. In the end, no matter what, Belichick treates everyone the same. Even the greatest quarterback of all time.