Please, watch the first hour of this video https://www.youtube.com/watch?v=snNPFl1PJNE The AO spells out each and every step on how admissions at UCLA works. Important at about 40 minutes in is UCLA does NOT use the UC Capped GPA. They use Unweighted and Weighted GPA and semesters of AP and Honors Course (honors courses are only considered for In-state).
I think an important point that was made is that each person gets two readers review their application. So that is part of the luck of the draw, who the reader is. Each person is an individual and brings there own biases on the importance of each application, from the type of EC’s, to the quality of the essay.
From looking at Student A and B, Student A is indeed strong academically, but as you can read, there are many with similar stats rejected. Student B is below average stats, so there must have been something about them that stood out to the readers. Maybe they requested a major that they are seeking more students, maybe the essays were compelling to the reader, you never know.
I think it is getting to the point that we are comparing applies, oranges, grapefruit and plums. There are so many top candidates and so many variables that you just can’t boil it down to a few stats.