The way I look at it if Brady at his peak level of his career, how many superbowls would he have if he were the quarterback of the Chiefs instead of Mahomes and the answer is:
0 vs the 3 Mahomes already has. I don't see Brady winning any superbowls in the shoes Mahomes is in. I don't even know if any QB in the league right now would make the playoffs with this Chiefs team.
People want to talk about the 7 Superbowls Brady has with the Patriots, but take any top 10 QB in that area and they would have won many of those same superbowls. Brady played an entire career without a need to wash his uniform. Great defense, great offensive line, just a perfect environment for a Quarterback.
I think Brady is a great quarterback, but think this undisputed goat status based on the fact he played on great teams is a little overdone.