It's Bill's fault. That's the one that kills me. The dude left of his own free will, but it's Bill's fault that he retired three years later.
Belichick was talking up moving on from Brady as early as 2014. So only 9 seasons too early. Brady made statements which made it clear he wanted to remain a Patriot but the team didn't reciprocate the commitment. BB facilitated the split, not Brady. But that's not really the point here and the split worked out bigtime in Brady's favor so let's move on from that.
Can we have a serious discussion about Brady's "retirement(s)"?
Brady will be 46 by the start of the 2023 season so it's not a major upset that he's retiring. However, he faked his initial retirement last offseason because he, Sean Payton, and Stephen Ross were cooking up a plan for Brady and Payton to join Miami for the 2022 season (and very likely beyond). I think Brady had the likely intention of playing 2-3 more seasons in Miami.
However, the lawsuit filed by Flores, alleging racial discrimination in hiring processes across the NFL, derailed Brady's Miami plan. Belichick was pivotal to that lawsuit coming to fruition. Firstly, Belichick participated in what Flores called "back channel conversations" that influence hiring decisions and denied him a "fair and equal opportunity" to earn a head coaching position.
Secondly, it was Belichick's text messages (mistakenly) sent to Flores that tipped him off. BB actually congratulated Brian Flores for "landing" the NYG head coaching job before Flores had even interviewed for the position. Problem was BB texted the wrong Brian when he had intended on texting Brian Daboll.
Once BB realized he "****ed up" he straight up lied to Flores and told him he had "misread" a text from NYG saying which Brian they had hired. When in reality he incredibly texted the wrong Brian from his contacts.
Flores proceeds with the sham interview, subsequently it's announced Brian Daboll gets the HC job for the NYG, which Flores already know from BB's text, and soon after he files his lawsuit.
Ultimately Brady was left with one option for the 2023 of playing for the Bucs. He "unretires", Arians steps away from coaching due to health concerns, and Brady ends up with toilet bowles who crushes his desire to continue his NFL career.
So my list is fair. In fact, I'll revise it slightly (BB jumps up a spot).
People most responsible for Brady's retirement (for good):
1. Todd 'toilet' Bowles
2. Bill Belichick
3. Brian Flores
4. Gisele