Isn't that correlation, not causation? It's entirely possible you could meticulously write 20 detailed cover letters, and get no response because you don't fit

Isn't that correlation, not causation? It's entirely possible you could meticulously write 20 detailed cover letters, and get no response because you don't fit the role or the hiring manager is swamped or any number of reasons. Whenever I apply for a job, I always take the time to write a good cover letter. Why wouldn't you maximize your chances?