This but he hasn't surpassed Brady overall... yet. Brady had the best vision and ball placement in the league for years and he was refining his motion and general game throughout his career. Best mechanics is easily Rodgers along with similar off platform to Mahomes. Mahomes may be best in the clutch and no denying that arm and awareness but he's only 1/2 way through his career. It's not just about rings as it's a team game but longevity matters when discussing a GOAT.
This is a fair stance to have.
I'm reminded of Roger Federer just absolutely dominating the tennis world in the 00s and into the 2010s. He was doing stuff no one had ever done before, was regularly collecting 3-4 majors a year, and was generally basically unbeatable.
He made it to something like 20 straight major finals.
Even before he surpassed Sampras' number of majors won, it was clear that Federer was the best ever. Federer was better and more dominant than Sampras ever was. But there were still people who weren't willing to go there until Federer surpassed Sampras on the majors list.
Were they wrong? In my opinion, yes. Federer was better. He just was. Even before he passed Sampras. But even so, it seems fair to expect someone to take the mantle on championships before they're crowned the GOAT. I disagree with that stance, but it is a fair stance.
Now, a pretty flimsy stance to have is, "Brady is better than Mahomes because the Chiefs are some amazing organization."