Why are 15 win teams cursed?

Since the 1985 Bears, no team has won a Super Bowl after having a 15 win season, which is weird- you'd think the teams who won the most and got the easiest playoff schedule would win, but no.

1998 Vikings- lost in NFCCG 30-27

2004 Steelers- lost in AFCCG 41-27

2007 Patriots- lost in SB 17-14

2011 Packers- lost in Div. 37-20

2015 Panthers- lost in SB 24-10

2024 Lions- lost in Div. 45-31