Hundreds of good applicants can’t be whittled down to a dozen without being very picky about things in the resume which may just be a poor representation.

You will bias heavily along some kind of axis, preferred previous employers or location, age, etc.

You add a lot of bias into the system by trying to further scrutinise otherwise meaningfully qualified people on paper.

As long as you aren’t biasing for any protected classes, why does it matter? If you as an employer have found that graduates from Foo University is a generally positive signal, then why wouldn’t you bias for that, if it’s saving you significant time, and introducing minimal false positives?

Yes, people don’t realize that’s why a lot of desirable jobs/grad schools become filled with people from top universities and previous employment. Pedigree is probably the lowest hanging fruit when it comes to shaving off a good chuck of applicants to a level that at least you know would be adequate.

Once again, you're misunderstanding the goal of the system if you think that it's necessary to deliberately whittle down hundreds of good applicants through careful process to get a great hire.

Hint: you don't even need to evaluate most candidates at all. Random sampling is sufficient and provably bias free.