Make sure you are comparing apples to apples and not cherry-picking studies to support your argument. As you know many studies do show very different outcomes for affirmative action students.
Why did you not quote this study?
"at the University of California at San Diego, affirmative action students had an average GPA 0.30 points lower and a graduation rate of 57% compared to 73% for non-affirmative action students"
https://www.jstor.org/stable/3699572
Why do different studies produce different results? They are not really studying the same thing, even though both claim to be studying "affirmative action". Since affirmative action can be done differently and that will produce different outcomes.
Do you think both universities administered their respective affirmative action programs the same way? How did those differences in how the programs were administered, produce the different outcomes between what you stated and the UCDD study found?
I have heard arguments from executives supporting affirmative action "light". Under this approach, you ignore skin color until you reach the end of your evaluation process. At the point, where you feel indifferent towards the remaining candidates, you introduce race and gender to the process.
Such discrimination avoids compromising on your desired outcomes (hiring good candidates), but based on the core American value of equal opportunity is "unfair". The white male is being denied the equal chance of being hired.
One might consider such " a goal" noble and virtuous but is discrimination okay or not. Does it matter how racism is used, rather than racism is always bad?
Haven't minorities and women argued in favor of equal opportunity for decades, now suddenly some are arguing that institutions should put their fingers on the scale?
Such a system should produce comparable outcomes with one that randomly selects people from a qualified pool. But if the same system were instituted but white men were given preference, clearly society would be "outraged". This hints to the reality, that values are being compromised for some concept of "the greater good".
Whenever societies begin to justify their actions as being for the greater good rather than promoting equality of opportunity all sorts of bias and corruption begin to creep into the process. I was reading not long ago; how black male professors were getting squeezed out of tenure opportunities by minority female professors based on their gender. Under their affirmative action program, black male professors scored a point for being "black", while black female professors scored two points... black and female. Does that seem fair to you?
Moreover, who decided that black female should be worth two points and black male only one. Turns out the Department comprised mostly of female professors developed the system to insure more opportunities to minorities especially women.
My interest in this area relates to my grandchildren. I have 7 so far. Five are mixed race African or Haitian/white. All future grandchildren will be at least mixed race Asian/white and whoever my two youngest daughters ultimately end up with. I want them each to have a level playing field when they compete for college admissions and job opportunities. When you have members of your family on all sides of this issue, fairness tends to drive you towards "equal opportunity" rather than equity of outcomes based on group identity.
