Of my ~600 markdown notes, 85 currently contain the string "news.yco". Some of them may be just feel-good pseudo-procrastination (inspiration for the blog I did not start yet) but others definitely shaped me as a person. A big percentage is relevant material for my main side-project - the note taking app for my note - for which I got the idea and various details from HN. Another is a bunch of good (and less good) books I found here and read.
I don't have a collection of Teslas and some bay area real estate to show for it yet, but it comes down to this: My day-to-day thoughts are massively shaped by the media I consume. I can spend all day contemplating some dumb /r/askreddit question or a novel take on Docker CI/CD I read on HN. I am pretty sure the second one aligns more to whatever the opposite of opportunity cost is. IMO, in the end, being knowledgeable makes you a better dev.
Also, I am practicing my English writing skill, so if I start this blog one day, maybe it will not even suck (and earn me all that tangible money, of course ;) ).