I've been in a team where hiring requirements have emerged through the filter of HR almost unrecognisable. Naturally, they're still objective requirements, so qualified candidates are filtered out before ever meeting someone who could judge if they're qualified. It gets noticed, but nothing happens. Of course it doesn't: you're stepping on important toes.
That's how it tends to work. Candidates are filtered out by non-technical staff, including openly using programs that filter out CVs missing keywords. In smaller companies, this even gets farmed out to third-party recruiters that have poorly aligned incentives.
How can we know if candidates are qualified? We never see most of them.
It's hard to imagine many things worse for productivity than bad hiring processes. But it's all just accepted.