its still good (as someone who found this site just couple years ago) but every once in a while someone links an old thread, you're partially right.

It's just selection bias. If those threads weren't great they wouldn't be linked. A better test would be to use wayback machine to look at a random date's front page and its threads.

Not in the same realm necessarily, but there’s a page somewhere on the site that shows the front page, but only from users with a certain account age. Interestingly, the last time I looked at it, there’s was a lack of a certain topic showing up.

It is, but when is the last time you’ve connected with someone interesting and taken the conversation beyond HN?