I am really hoping LLMs will remove much of the cruft from our daily communication.

If cover letters are not a human effort any more they can be left out.

Recently I was involved in supporting my manager in hiring for a new Developer position and we barely even skimmed the letters. They are already basically useless

Agreed. In my most recent round of hiring, I used the presence of a relevant cover letter as a point in favor of the applicant when deciding whether to invite them in for an intro call. It showed me the person actually looked into the company a little bit and wasn't just spamming. It also helped weed out the spam since I'd get cover letters telling me how excited the applicant was to work at a web3 fintech while we're doing almost the exact opposite thing. Don't get me wrong; I think like 85% of people I invited back for calls did not have a cover letter, but it really helped in the weeding process.

If it becomes an effortless throwaway generated by an AI, it no longer has value. Additionally, you may be shooting yourself in the foot. If I see something in a cover letter that catches my eye, I'm going to bring it up in our call to learn more. Not to quiz you or play gotcha, but because it probably intreagues me and I want to learn more. If an AI wrote it and you don't know what you submitted to the job posting, that's not going to reflect well in a call.

Unfortunately, there is a massive sale going on for bullshit at the moment.

It's not surprising that people are trying to start businesses which would not be viable in a market where bullshit was more expensive.