It’s hard to compare “Hall of Famers” when Brady and especially Mahomes and the players around them aren’t eligible for the Hall of Fame yet.
I believe Montana is the GOAT, but time may prove me wrong.
Mahomes has been in the league six years. In six years one can still get a sample of who has potential to be in the hall of fame, from who has played in the Super Bowl with him. From the offense, other than Kelce I do not think of any. Tyreek Hill is a possibility - but Mahomes has won his last 2 without him (and many though KC would not be as good once he was traded).
You can definitely tell with Brady - in 22 years one can easily evaluate the players around him for Hall of Fame potential. He had many who might be in the 'Hall of Good", but other than Gronkowsi there may not be other sho played with him a long time. Randy Moss did had 3 of his years in NE but only made the SB once, in their almost undefeated season (thank you, G-men!
). But I do think that was part of Belichick's strategy as coach and GM, to not hang onto players for too long, perhaps due to salary cap management (Brady renegotiated his contract more than a few times to open up cap space).
But that does bring up another point, since modern free agency did not start until 1993. Team before that had more or less a stranglehold on players, so great players were more likely to play longer for a team, making team chemistry more consistent.
In my view the GOAT QB ranking now is Brady, Montana, Mahomes. But Mahomes, with a greater range of skills, has a great chance to pass Montana and approach Brady, only time will tell. I am just glad to have seen them in (so far) all the years of there careers, even if they did not play on the teams I root for
.