HN doesn't have read/unread flags for comments AFAIK.

I use the collapse thingy as a read flag - if I'm fully sated on a to and fro for a topic I might come back to I'll collapse the thread.

Future me will often un-collapse the thread through curiosity of course, but will quickly realise I was right

There is a Hacker News Comment Highlighter add-on both for FF and Chrome based browsers. Highlights what is new after a refresh.

I couldn't use HN without this.

Ooh nice. Ta for the suggest

nnhackernew.el presents HN as a 90s era Usenet forum.

That was, in fact, my point.

Most discussion systems are inferior to 1990 Usenet, 34 years later.

At this point it is traditional to shout about Usenet not having good moderation. In fact, it is possible for either individual news groups or specific news servers (that only carry a limited number of groups) to have good moderation. It is, of course, expensive: you need to get enough trustworthy people to run it to cover the time and volume.

Then someone will sniff about not wanting to use a TUI, which can be rebutted by pointing at all the GUI newsreaders -- having a standard protocol for talking to a server is quite valuable.

"Isn't Usenet a huge space and bandwidth hog?" Yes, Usenet was a huge space and bandwidth hog -- in 1990, and 2000. If you don't carry the warez groups, it can be adequately handled on a high-end server from 2000 -- which today is equivalent to a Raspberry Pi. (1994: 7 x 2 GB SCSI disks, 1.5Mb/s Internet connection)

HN approximates the activity level and content size of 1 very active Usenet newsgroup.