That's why feedback is important. If the reason was "we are looking for X experience and X is not on your resume" I can adjust that for later. If it was even as honest as "we found enough qualified candidates to interview and didn't look at your resume", that's still semi-actionable feedback. I either apply earlier or just accept that I was unlucky and it was not my ability.

Generic rejections like "we moved with other candidates" tells me nothing. So noise remains because candidates don't have feedback to improve upon. All because HR wants minimize lawsuits through obscurity.