I think we are all pretty aware of how the up and down arrows are supposed to be used versus how they get used.
For content that doesn’t trigger an emotional response: the arrows are used appropriately, highlighting comments and silencing less useful discussion. HN is incredibly useful for discussion on non-controversial, almost mundane, topics.
However it all comes undone for any topic that carries emotional baggage. Where up and down arrows are clearly used as “like” and “dislike” buttons regardless of the facts or merit presented in each comment. Instead commenting becomes an exercise in PR. The first clue is the comment count. HN has some very predictable patterns in comment counts.
Platform operators may not be willing to change this as “hive mind” and “liked” content helps visitation, even if it doesn’t help discourse. The consequence of inaction however is that topic experts are pushed out by mobbing, because invariably not everything is sunshine and roses.