I find a lot of interesting, neat articles on HN. Occasionally but rarely something worth talking to coworkers about.

Not once can I recall reading something on HN I had no experience with an being able to use that at work without doing a lot of additional research. In terms of time spent and career impact HN is on the same level as Reddit, which is a net negative.

Conferences aren't necessarily a net negative but who wants to spend 2-3 days going to talks and all the after party stuff (which is where real career progress is made) to get one or two solid technical bits? Especially when those will be available a week later in countless blog recaps?