Brady needs this AFC Championship badly. Overall, he has played poorly in the postseason since the Pats last won a SB. If the Ravens beat the Pats on Sunday (which I don't expect to happen) then the latter half of Brady's playoff career will be downright disappointing. Brady is a better QB now than he was when he was young, yet young Brady is the one with the rings.
If he wins the Super Bowl this year then yeah a lot of people will have him as the greatest ever. It would be tough to argue with 4 rings, most playoff wins, a couple of MVPs, a 50 TD season, etc etc.
If Brady had played better against the Giants in the Super Bowl four years ago then he would have already had the GOAT label locked up. I know he led the Pats on a potential game winning drive, but the fact is his offense had only put up 7 points prior to that against a team that they hung 38 on a month prior. Brady didn't play good enough in a game that would have made him immortal. No one would have ever been able to tough a 50TD undefeated season that ended with a 4th ring.