Or they could just publish a log of actions, this isn’t such priceless information that we couldn’t just rely on trust like we already do in the current situation that seems to work well.
You're providing a solution that doesn't fit the initial requirement of a system being trust-less. So, indeed, your solution works, but as you described, it requires trust in the administrators of the website. The idea of web3 is that you wouldn't. "Trust but verify", if you want.
This could be used for Facebook or Reddit (given that they solve or attenuate the issue of fees), where people might have less trust in the administrators.
I'm just saying that HN has no need to be trustless. I don't see the value of that as a user.
For stuff at the scale of Facebook and Reddit you'd also probably end up needing caching as the chains would be too slow so you end up needing a layer of trust anyway.
