I feel this perspective gets lost a bit. Big companies don't roll through 1000 applications with 50 open spots and try to hire the best 50 candidates. They want to find maybe people in the top quartile of that, while spending the minimal amount of time on costs to find the adequate fits, and the cost of a false positive is way higher than the cost of a false negative.

Is the process great? Absolutely not, and I'm sure that these places miss out on qualified candidates because of the process and hire some people who gamed the process. Things like degrees and LeetCode tests and other screening methods are just ways to reduce cost and risk to get that "good enough" threshold.