Everyone knows it's broken, but interview cycle still continues to bring in talent, even if there are false negatives. People still brave the grueling gauntlet. People still show up for interviews. Smart people still get hired. The system works, just in a terribly shitty way.
To HR, the engineer hiring process is voodoo magic and we best not touch it.
It only works because there's always another body standing outside the door waiting their turn to be abused by the process. It'll end real quick if they run out of interviewees.
A small agile company could hire undervalued people who don't do well in traditional interviews and clean up, if they didn't cargo cult programming interviews.
See these make a bit of sense for huge companies that have to filter millions of potential candidates. They don't make sense for your ten person bootstrapped company that wants to hire a junior full stack dev.
To HR, the engineer hiring process is voodoo magic and we best not touch it.