Clearly, the best way to compare conference quality (and program quality) is head to head competition.
It’s the best way, but not a perfect way.
For one thing, there is the jihad factor. In 2022, for example, the three top games Texas circled were Alabama, Oklahoma and TCU (the last is my guess, due to Sark working for CDC. If you offer a different “third circle”, I won’t argue). Meanwhile, Oklahoma, OSU, TCU, TT, ISU and Baylor all Texas circled. Game results and objective measures don’t care about jihads.
For another, the main source of inter-conference competition is bowl games, and the non-playoff bowl games have become pure exhibitions. That fact (I believe it is a fact) is only gradually being recognized. It was a lot of fun watching OSU edge the Aggies last December, but, with the sit outs, the lame ducks and the transfers, does it really say anything about program quality?
Finally, I’ll refer you to the 2022 CFP semifinal between TCU and Michigan. TCU QB Max Duggan carried the ball 15 times for 57 yards and two TDs. The running QB is college football’s cheat code. Problem is- the QB needs to be the size of VY or Cam Newton if he is going to do it two games in a row. Duggan isn’t, and his body not being right contributed to TCU’s embarrassing thrashing by UGA.
The SEC has a good record in inter conference play. It has a fantastic record in CFP and BCS CG play. I suspect the expanded playoffs will see plenty of B12 and ACC teams win one game (“We’re every bit as good as you are!”) and very, very few win two in a row.