I haven’t noticed that at all. Whenever I see an argument made in good faith, there’s frequently contrary responses that delve into the actual issues and discuss some of the nuance around them. I found Reddit far worse (especially the default subs).
On Reddit, any comment reply I got was usually someone telling me to kill myself or correcting some boring pedantic thing. On Lemmy they usually make me think about the issue some more, and they’re never frothing-at-the-mouth aggressive.
But it might also depend a lot on what communities you spend time in, what instance you’re on, and what instances you have blocked.