I'm not saying you're wrong and anyway it is hard, if not impossible, to evaluate objectively—but I can tell you two things for sure. One is that people have been saying more or less exactly this about HN for at least 15 years; the other is that HN is subject to a lot of random fluctuations, and random swings tend to get interpreted by humans as long-term trends—not because they are, but because that is what humans do.

In addition to my sibling comment: HN also steps in to quash developing negative patterns in all sorts of ways. There's a long list of banned sites, there is the flamewar detector (though I've ... questions ... about that), dupes detection (or flagging), there are weightings and penalties given to various sites. I believe also some keyword and other patterns are looked for as well, "Reddit" being among ones dang's recently discussed.

So yes, occasionally some new pattern or trend will emerge, but HN adapts to those fairly quickly.

* * *

More on "UNCLASSIFIED": there are 36,520 of those sites.

It's not practical to list all of them. But we can randomly sample. And large-sample statistics start to apply at about n=30, so let's just grab 30 of those sites at random using `sort -R | head -30`:

   1  sfg.io
   1  extroverteddeveloper.com
   2  letmego.com
   1  thestrad.com
   2  bombmagazine.org
   1  domlaut.com
   1  bootstrap.io
   1  jumpdriveair.com
   2  desmos.com
   1  leo32345.com
   1  echopen.org
   1  schd.ws
   1  web3us.com
   7  akkartik.name
   1  bcardarella.com
   1  cancerletter.com
   1  platinumgames.com
   1  industrytap.com
   2  worldoftea.org
   1  motion.ai
   1  vectorly.io
   2  enterprise.google.com
   1  lift-heavy.com
   1  davidpeter.me
   1  panoye.com
   3  thestrategybridge.org
   2  fontsquirrel.com
   1  kettunen.io
   1  moogfoundation.org
   2  elekslabs.com

That's a few foundations, a few blogs, a corporate site (enterprise.google.com), and something about tea, all with a small number of posts (1--7).

I'm looking at some slightly larger samples (60--100) here on my own system, and can actually make some comparisons across samples (to see how much variance there is) which can give some more information on tuning what I would expect to find under the "UNCLASSIFIED" sites.