I will say this about Brady, it's pretty apparent that he was a bigger part of Belichick's success than people give him credit for.
The Patriot's post Brady have been mediocre at best.
But Brady was slick. His contract left the Patriots with tons of dead money when he left, and that has had ripple effects for multiple years. Additionally, he went to a team that was strong everywhere except QB, knowing full well that he would get more of the credit than he deserved if he went there and performed reasonably well, and as a result the team was able to make a deep playoff run or even win a title.
Also, people keep forgetting that through his 20s, Brady was a decent-but-nowhere-near-great QB. He didn't have his first Peyton Manning-level season until age 30, and then he maintained that level for well over a decade. The debate when Brady was in his 20s was about Brady the "game manager" with more titles vs. the otherworldly sport-altering performance of Manning as a QB on $#!+ty teams. There were Colts teams that could best be described as "Peyton Manning and some guys" that Manning managed to drag to the playoffs. Brady never had to do that, because Belichick always had a solid-or-better team around Brady. Brady the game manager was enough for the Patriots to win their first three titles just because those teams were so strong overall.
If you look at Brady's career trajectory, you can see a peak around age 27 that would be about what you'd expect from a decent-but-not-great QB, and the beginning of a normal decline from that peak. Then suddenly at age 30, Brady had a season that was three times as valuable as his previous season, and more than twice as valuable as his previous best. When I say that's suspicious, it's a massive understatement. Other players have been tried, convicted, and executed as cheaters in the court of public opinion for a lot less.
It's kind of hilarious that Wilson tried to "pull a Brady" by vetoing trades until the Broncos, a team that looked a lot stronger than the Seahawks everywhere except at QB. I'm guessing he thought he was going to make the Broncos a title contender and that the Seahawks would be among the worst teams in the league. But he ended up sucking so much that the Broncos were among the five worst teams in the league, while the Seahawks made the playoffs. Instead of "pulling a Brady" and cementing his legacy, Wilson's total suckitude in 2022 made "cement shoes" for his legacy. That makes me chuckle every time I think about it.