I’ve also seen a ton of cases where people expressed disagreement or contrarian positions but did so in a respectful and fact-aware manner and had positive interactions because they were respectful of the community.
Positive interactions are certainly possible and do happen, but the site is heavily heavily tilted towards groupthink. Fighting it is an uphill battle.
Users rarely deviate from the established upvote/downvote patterns. In fact, I'd go as far as saying many users don't even read the comments before voting.
When two users are having a heated argument, it's common for a third person to respond to the 'right' person with an innocuous comment and be heavily downvoted for it.
Note also how I mentioned people repeating low-effort arguments. The tedium comes from the stream of people who come, repeat someone else’s idea, aren’t prepared or willing to engage intellectually, and whine about censorship when nobody finds that compelling. Anyone who spends much time in a particular forum can recognize that and see that there’ll be very little value from engaging. We see that a lot here where people complain that HN is biased against cryptocurrency because the response to “have you accepted our lord and savior bitcoin into your heart?” was not well received by people who remember the exact same claims being made a decade ago.
This is 99% of Reddit though.