58 players were drafted from the Big 12 from 2011-2021. So that's 0.53 per school per year.

83 players were drafted out of the PAC12 from 2011-2021. That's 0.62 per school per year.

That also doesn't reflect how imbalanced the draft picks are from the Big 12. 29.3% of the Big 12's NBA draft picks come from Kansas, so if you're at a different school, your draft odds are a lot lower.
UCLA is responsible for the highest percentage of PAC12 draft picks over that time frame, but it's only 18% of the drafted players.

If I want an NBA career, I'd choose Kansas over any other Big 12 or PAC12 team, but Big 12 (surprisingly) doesn't have an advantage in getting players into the NBA, as compared to the PAC12. Clearly the Big 12 plays better basketball though. Not sure why, but could be something about PAC12 guys being drafted on potential or Big12 guys staying longer.