The staggering difference is the bottom 3-4 teams in the Big 12 are typically drastically better than other major conference bottom teams most years and it's been that way for a solid decade since our deadweight basement programs left for Big Ten and Pac making those conferences worse and ours better.
The ACC and SEC especially always have a solid top 2-3 that could beat or play with our top 2-3. The bottom three of all of these other conferences are basically a scheduled win for the best teams, not the case in Big 12. The Big Ten has been exposed as an overrated media creation by the tournament most years. Any one year can be a fluke but it's a super long trend now. Big East, while not in it's glory years, still has years here or there where the top is very good, after one round I'm still not sure about this year.
Will be interesting to see if B12 crazy depth changes. At least UCF is not ready for Big 12. We'll see how BYU/Cincy react. Houston will go from top 5 team to top 20 team most likely. Same would be true for Gonzaga if they joined, they'd probably be ranked 18th or something right now with a Big 12 schedule, they barely have a better record than KU and they play in the WCC.