Very true! I find it disappointing that many candidates appear to put little effort in their cover letter. It's a chance to show me you can communicate well, which is maybe the single most important skill in working on a team.
I feel like cover letters are an easy way to show that you've thought about the company you're applying for, but in my experience I've never got the impression that my cover letter was actually read in the application process.
I could be plenty wrong though, and I'd love to hear from HR/recruiters about their experiences with cover letters.
I dunno. I'm sure some places don't read them at all. But I read (or at least skim) every cover letter that comes across my desk before looking at the resume.
Which makes it extra frustrating that hiring practices are the most often cargo-culted practices in this industry. I feel like the root of hiring problems is that most companies know neither what they need or how to identify those features in a candidate.