I don't really like going into the wayback machine, but for you I will make an exception since I agree with what you wrote.
The fracture happened as Bill chose to stick with his "move on a year too early", "no one is above the team" mantras late in Brady's tenure here.
I could see a theoretical scenario where Bill chose to make an exception to those rules due to Brady's obvious greatness, but only in theory.
Bill already thought he had a path to move on from Brady earlier with Jimmy G, but Tommy outplayed his expectations in 2017 and 2018.
From that point on, it seems both guys no longer were very comfortable with each other, and both knew the end was not too far in the future.
Fans would have loved the outcome where both Bill and Brady faded into the sunset together, but IMO by the end neither guy was up for that.
To me it's bittersweet that it ended the way it did, because it's clear to me that Brady joining Tampa in 2020 was indeed a "no-brainer".
He knew he'd be joining a team with Godwin, Evans and Miller already waiting for him, then Gronk, AB and Lenny joining shortly thereafter.
How did he know? Well he did get caught on the Miami owner's yacht before he was a FA so we know he was being pro-active.
At the same time Tom would not have won anything with the 2020 Patriots WRs, namely Damiere Byrd, N'Keal Harry and Jakobi Meyers.
Tampa put their money where their mouth was by putting two years and $50M on the table when no one else was offering him that.
Tampa took their chance and made it a no-brainer, BB had the chance a year earlier to extend him on agreeable terms but didn't.
I don't really see why/how to assign blame, it feels to me more like things had just run their course.
If Bill had extended Tom late in his career neither would be happy and the team wouldn't have been good.
Tom was enough to put Tampa over the hump in 2020 but in 2021 he had lost his locker room and his wife, so another bittersweet ending.
Now what we have left is Bill and Robert more or less roasting each other with Tommy actually getting roasted live by some of the best comedians in the world.
Not a very glorious end, says I. No one is covering themselves in glory, IMO.
Appropriate to the spirit of this thread was Tom taking a huge shot at Bill at the roast:
The funniest part to me is that she's not poor any more.
Ref:
The MVP’s & Best Jokes From The Roast Of Tom Brady
Both should have just let the past be the past, but it seems neither are disciplined enough to do so.