If you want to work with a think tank, a nonprofit doing exciting and important work, a startup with an amazing idea that really captures your imagination, or any other org where the big picture needs to matter as much or more to everybody involved than the content of the PRs, then the cover letter likely matters more than the resume.
No judgement. I use those top 5 products. It's just pretty myopic to deem cover letters as unnecessary when that's only true for people with very specific goals and ideas about what matters in a job, even if they happen to be very common.
I didn't suggest this, at all. I suggested the value of a cover letter is not some constant across the tech sector, from startups (sample size = 2) to the big 5 (sample size = 2).
https://news.ycombinator.com/item?id=15934135
I wish I could find the golden comment of an HN user realizing that he has used cover letters to exclude candidates, but he can't do that for those who didn't supply one - putting the latter at an advantage.