Potential "dynasties" that Brady has stamped out:
2001 - The Rams had won in 1999, had a 2-time MVP quarterback, the Greatest Show on Turf. Ricky Proehl announces, "A dynasty is born tonight." If the Rams had won, likely they would have been considered a dynasty. Pats win 20-17. The Rams promptly go 7-9 the next year, and don't make it back to the Super Bowl until the 2018 season where they meet Tom Brady and the Patriots.
2004 - The Eagles had been to the NFC Championship game 4 years in a row, finally winning it in the 2004 season. Winning it would have set them up to be a potential dynasty, given how dominant they'd been. Pats win 24-21. Philly promptly goes 6-10 the next year, and don't make it back to the Super Bowl until the 2017 season where they meet Tom Brady and the Patriots.
2014 - The Seahawks were the defending champs, having obliterated Peyton Manning and the Broncos the year before, and boasting superstar Russell Wilson and the league's #1 defense. On the verge of back-to-back titles, the Pats win 28-24. Seattle goes 10-6, 10-5-1, and 9-7 the next three years, and they haven't been to the Super Bowl since.
2020 - The Chiefs are the defending champs, though the year before Brady, then with New England, had knocked them out of the playoffs in the AFCCG. On the verge of winning back-to-back titles, Brady and the Tampa Bay Bucs have the chance to put this talk of a Chiefs dynasty to bed.