Hacker news is the only thing I use close to resembling social media. I am basing this off of people I know in real life, youtube channels and small talk before my zoom meetings. The difference in people having a position in the matter seems stark. Perhaps it's less controversial of opinion one way or the other so the rage bait isn't their to be reaped.
HN has its own share of extremism, uninformed opinions, and misinformation, just like any other social media. The participants here are just more civil and articulate.
These companies are not simply a mirror back at society. People were interested in Rittenhouse because they were told that it was important. They could have elevated one of dozens of shootings by minors last year to media sensation status if they so chose.
The Rittenhouse incident was all over the internet the night it happened. It dominated Facebook, Reddit, and Twitter while armchair detectives scrutinized every leaked cell phone camera angle and posted their hot takes.
The media didn't tell people to get interested in it.