Insane that this is from 2021 and I've only found out about it now. The Internet is slowly but inexorably getting locked down, and the bitter reality is, there's nothing we can do to stop it.
I don't disagree. But to be clear, I wasn't surprised that I missed it on HN, but that I missed it period. There was a time not so long ago when such a thing would be inconceivable.
I don't think they were implying anything other than surprise that they missed it. Obviously not everyone is on the site every day so the concept of a "dupe" is really a leaky abstraction, and all the passive aggressive comments calling out dupes and old content are annoying and misguided.
You'd need something like an index or an archive. Something you can catch up on while skipping what you have seen.