I have been on HN for 15 years, I have spent far too much time on this site. Eventually you learn which topics will be "toxic" and avoid them (if you want to). To some extent it just maturity (or lack there of) but I actually think HN is far less toxic outside of some specific topics than other sites.
The topics that are liable to become flame wars change over time, currently it seems to be anything "Crypto" or "Online Advertising" as people have very strong feelings on both sides. I'm certainly still guilty of getting drawn in at times, especially when I feel I have a horse in the race. There is always insightful comments in these threads too.
Fortunately HN is designed to detect topics that are getting out of hand (far more comments than up votes) and they drop of the homepage quickly massively reducing the exposure. Exactly where this thread is already going.
I think the best decision HN made was not breaking the site into categories or "Sub-HNs" where specific toxic topics can grow and mutate, everything is forced though the front page ensuring a level of self moderation.
After 15 years on the site I have no intention of leaving it.