As a person who gets paid convert knowledge into product, HN is an easy place to check a once or twice/day to keep up to date on decently filtered knowledge/information. I have other sources I follow, but as you said, if it hits HN it's probably important enough that I should know it exist.
And yes, this is a vague answer because that base level knowledge can manifest itself in many ways when solving a problem.
In order to keep the EV/time positive, I have become more disciplined around which articles I decide to read the comments on.