I'll be honest - as much as I hate to say this (because I love that BYU is going to the Big 12), I don't think the Big 12 is an equivalent conference to the Pac-12. Since 2014 when the CFP started, the Big 12 has been a lesser conference.
I'm just talking football because I don't care about any other college sport.
If we look at the competitiveness of each conference based on how many teams finish the season ranked in both the AP and CFP rankings, and if we look at the Big 12 as it will be in 2024 with the new incoming teams and without OU and Texas-
Since 2014-
The Pac-12 has more teams finish in the final AP and CFP rankings than the Big 12.
The Pac-12 averages more teams finishing ranked in the final AP and CFP rankings than the Big 12.
The Pac-12 has had two teams represent it in the playoffs vs the Big 12's one team.
Without Oklahoma (and a lesser degree Texas), the Big 12 is seriously watered down.
I would rank the P5 conferences thus-
1. SEC
2. Big Ten
3. Pac-12
4. Big-12
5. ACC
This season has been great for the Big 12 and horrible for the Pac-12, but when you look at the historical data, it's an exception, not the rule. Hopefully, that starts changing. All of our Pac-12 hate relies on the fact that we have a very shortsighted viewpoint, but when you look at the bigger picture, the Pac-12 has been a stronger conference.
I'm just basing this off of pure data. I'm not a kool-aid drinker so go easy on the hate.