While I'm not really active in the forum in general and thus not getting in a lot of arguments, I still see where you come from. I wouldn't call certain things "toxicity" per se, but rather a lack of knowing how to express one's opinion in a constructive manner - even though you don't agree with a person. After all it's so much easier to address an issue just with "I hate this or that idea, that is so stupid!" than finding and expression reasons for why someone doesn't agree with the other person.

I don't really want to blame people who behave like that to be honest, sometimes we just have a bad day and/or just get annoyed by the "weird" idea someone has and just want to express that. I often caugh myself doing that too, but before I even start writing I ask myself: "Can't I spend this minute more productive than writing an angry sentence how stupid someone and their idea is?" Yeah, I know, it's only a minute, but which is better: Making some tea/grabbing your favorite food/watching a cat video on youtube or attacking someone online, even though they and their ideas won't really matter in your life?

I know it's not always rainbows, unicorns and butterflies and it never will be, but most of the time there are definitely better and nicer ways for both sides to communicate over a problem. If you really want to express your opinion in a way that might be toxic, go ahead - but don't be surprised that the other side gets really defensive and thus making your day at least a little worse.