Not that this doesn't have credence, but I keep being blown away by how often ND is pitted against a playoff caliber team in their BCS/NY6 bowl game. The Fiesta Bowl last year was the only time I recall them playing a remotely beatable opponent in one of those bowl matchups.
2000 Fiesta Bowl: Oregon State led by Ochocinco and the Hoosh.
2005 Fiesta Bowl: Ohio State led by Heisman Winner Troy Smith, Ted Ginn and Santonio Holmes.
2006 Sugar Bowl: LSU with pre-drank Russell.
2012 NCG: Probably the 2nd best Alabama team under Saban.
2015 Fiesta Bowl: Ohio State team that had 8 starters go in the first round of the '16 and '17 NFL drafts.
2018 Cotton Bowl: Half of Clemson's defense went in the first round the following 2 drafts.
2020 Rose Bowl: The best Alabama team under Saban.
Then I look at some of these teams' bowl wins:
Wisconsin (beat 8-4 Stanford in the '99 Rose Bowl)
Iowa (beat 10-3 Georgia Tech in the '09 Orange Bowl)
Michigan (beat a mediocre VT squad in the '11 Sugar Bowl who got obliterated by Clemson in the ACC CG)
Nebraska (beat 9-3 Tennessee in the '99 Fiesta Bowl)
Penn State (beat 8-5 Florida State in the '05 Orange Bowl / beat Memphis in the '19 Cotton Bowl)
Ole Miss (beat 10-3 Oklahoma State in the '15 Sugar Bowl)
Texas A&M (beat 8-4 North Carolina in '20 Orange Bowl, while UNC was missing practically their entire offense)
Georgia Tech (beat 10-3 Mississippi State in the '14 Orange Bowl)
Virginia Tech (beat 11-3 Cincinnati in the '08 Orange Bowl)
Iowa State (beat 4-3 Oregon in the Fiesta Bowl...really? 4-3?)
Baylor (beat 10-3 and Corral-less Ole Miss in the '21 Sugar Bowl)
Kansas (beat 11-3 Virginia Tech in the '07 Orange Bowl)
Washington (beat 8-4 Purdue in the '00 Rose Bowl)
Oregon State (beat 9-3 Notre Dame in the '00 Fiesta Bowl)
Houston (beat 10-3 Florida State led by Everett Golson in the '15 Peach Bowl)
Those are some pretty forgiving draws that ND simply hasn't gotten. I don't think a single one of those teams is as good as '21 Oklahoma State.