The "meritocratic process" is laughable. Legacy admissions have always been a critical component of those systems, especially once wealth was no longer an adequate filter; allowing a few newbies through the sieve in order to conceal the real purpose of the ivies—perpetuation of an elite caste—has been the game for a long time. As universities are pressured from the left (getting rid of standardized testing) and right (getting rid of any sort of racial consideration in admissions), legacy will only become more important as an attribute. That a few people beat the odds doesn't at all imply that the system is fair or that that solution is scalable.
"Culture fit" is realistically both important and historically has been a really problematic thing to conflate with or consider alongside "merit." It is a tough problem and I don't have a great answer to it.