I was certainly being a bit overly cynical with a lot of what you're replying to, but I think a lot of that is driven by not earnestly believing that most companies are as earnest and caring about this as you seem to be. I can write an earnest cover letter about what I love about computing and my job, and what I want to do, and how a new role I'm applying to excites me and speaks to what I find interesting about this sort of job. I've even done that 3-4 times in the last year. And you know what?

I got literally not even a rejection letter from any of the places I put at least half an hour of me spilling my soul and passions into a cover letter for.

I literally think I've had a worse track record of getting a first round interview when I provided a cover letter than when I didn't. Small sample size for sure, but I'm actually unsure I've ever had a cover letter even get acknowledged, let alone get me in the door.

To turn your analogy, most companies and job postings feel like them saying "I'll buy you nice dinners, take care of your kids, and cover your expenses as long as you have sex with me." And honestly, at some point, I've been mostly beaten down to the point where that sounds good, because the companies that promise me they care about me and want to learn about my interests and go on a nice date with me don't even acknowledge my existence when I send them a love letter.

I've been curious about this recently, and have been asking around my network, and I actually don't think anyone I've worked with who's done interviewing for their company has ever even seen a cover letter as part of an interview packet. You seem to work somewhere that cares and would actually read and process them, but if so, you really need to make it clear that it actually matters, because at this point, I've had too many companies even require a cover letter and then seemingly care less about treating me like a person than I treated their job as something I could be passionate about.