I think the Chiefs are already a historically notable team and that Mahomes is an all-time great. I get annoyed at a couple of narratives.
1. Mahomes joined a team that was winning 10/11 games and their division every year. Brady joined a team that was 5-13 and had no hope of competing in 2001. National narrative is a 180.
2. This is more about every QB compared to Brady, but especially Mahomes recently. Brady was not only playing before multiple rule changes favoring the offense, but averaged a full touchdown more than Bledsoe (a pro bowler and highest paid QB in the league) but in 2001 had absolute garbage for skill players. From 2002-06 this fluctuated between garbage and semi-garbage. Trying to compare TD passes, passer rating, yards, etc in a different era and with that relative talent gap is disingenuous. We all saw in 2007 with Brady. We can confidentially say those raw numbers from 2001-06 would look much, much different with guys like Tyreek Hill, Travis Kelce, Marvin Harrison, Reggie Wayne, J’Marr Chase, etc.