Much has been written about how much time an assistant professor should spend on "service" work and what types of service might be important for career advancement, as opposed to a poor use of time, not to mention soul-destroying. The typical advice is: "do some but not a lot."
Search committees often place a great deal of importance on cover letters when they're reviewing candidates, but I've yet to meet a job seeker who has received much training or mentoring on how to write one. So what differentiates good cover letters from weak ones?
"It's hard to give people a path to follow when, by your own admission, you stumbled upon your current career. Serendipity seems to be a theme in many alt-ac narratives, and that is just not inspiring to students who are worried about their futures."