Other than it being run by, and on behalf of, a SV startup accelerator, and being part of the SEO strategy for any number of startups and wantrepreneurs, and many posts (particularly in Show HN) being thinly veiled attempts at advertising, building hype or just trying to get money-senpai to notice them.
Other than that, sure.
Only the rank relative to other web sites has dipped,
If that was true, HN wouldn't exist.
> That’s one of the things I like most about the site, a complete lack of monetization.
But jobs are advertised here.
> It’s pure in this sense.
It's better than most, but it certainly isn't pure.
Serious question - have they ever proven to be reliable?
Seems to be Alexa's bug, not HN's.
It could be that there are thousands of sites with a similar number of visits. A small drop in number of visits might cause a huge drop in rank.
Also when a site has been around for long you have to start taking into account the 'population growth'; how many new people gained access to the web this month? How many among those are tech-savy people? Does this proportion increase or decrease over time?
But there definitely has been a significant drop in keywords where HN is displayed on Google (probably because of the major algorithm “Medic” update on August 1st): https://i.imgur.com/qCTC0xd.png
I note that for ycombinator it makes it clear figures are an estimate. To get proper stats you need to embed some JS, right?