Online text based chat does seem to encourage arguments.
I think you're probably correct here. Text based chat lacks tone that allows you to convey emotion or certain feelings. It's hard to express things like sarcasm over text, for instance. It can turn what might be a harmless quip in regular conversation, into down right fightin' words if read the wrong way.
With the virtual nature of it.. I'm not sure. The anonymous nature of the internet probably gives a lot of people the courage to say things they probably wouldn't say to someone face to face.
The one thing about forums though, is it does tend to feel like a smaller space. There's less of a feeling of "We're all strangers here" that you get on other areas of the web, like Reddit, or X.
I've been posting here about a year. ENWorld has probably thousands of members, but I have gotten to the point where I recognize two... maybe three dozen of you by your avatars, usernames, and even the way you chat. While I don't know if this makes this a small community, it makes it kind of feel like one, and I think a lot of forums have similar vibes. This can probably lead to some bad habits. For instance, if there's one particular user you feel like is a bad actor, or maybe you've have a bad experience with them in the past, you're likely to be less charitable with them in the future due to that pre-existing bias and maybe more prone to argue.