Sure, it happens here, but I feel the toxicity on Lemmy is far less then on Reddit or other platforms, and with toxicity I mean including people assuming you're saying something else because they are triggered somehow. But it's very hard not to stumble upon people like that. Trolls rule the universe, they are everywhere.
But I'm glad I don't have to scroll through loads of right wing extremist posts all the time and constantly have to fight nazis. nazis.. nazis... nazis....
Just personally, I find that the toxicity around here just around group think is a little worse than reddit. It's different but it can be a lot worse, especially with the way people on Lemmy use downvotes.