Comments don't get collapsed when they are flagged, they are collapsed by moderators manually.

Either way, the system clearly works.

It was flagged because I pointed it was useless.

I can't make a comment asking every single fluff comment to please elaborate a bit more just so people go "oh, huh, yeah this shouldn't be here". And you can't deny that in the last N years, HN has become more and more happy to upvote fluff.

I can indeed deny it. I think you are also giving yourself too much credit. I would be very surprised to see a comment like that one not at least colored grey, even without your heroic involvement.

You can deny it, but you'd very well be wrong. You've been a user since 2017, so I understand if you're not familiar with what the discussion looked like circa 2014 or so, but it used to be much less tolerant to the low-quality comments that get posted nowadays.

This user is from 2017. I've read Hacker News for a long time. I think you need to get over yourself a bit.

Downvoting works, and it takes very little time.

Neat but I read the site literally every day and have posted for years and don’t have the ability to downvote. Perhaps I’m on a blacklist of ex-slashdotters.

There’s a karma requirement. If I recall correctly I gained the downvote when I passed 500, but I could be wrong of course. My impression of this site is that they don’t do blacklists, they’d probably warn you straight up if they had a problem.