I feel the opposite. Online I get to complete a thought. In real life, my points that are more than three words ("cats are nice") gets cut off, taking the conversation in a new direction. Moreover, people tend to think everything I say is an insult to them. It's only a slight exaggeration to say when I tell someone "you're hair looks nice today" they will respond "I'm not a scumbag! And I never killed that guy, he took too much coke by himself! Oh god, mommy, why did you never love me." That escalated quickly.
Online, your attention is on the online. So when you're reading my post "cats, be they domesticated or otherwise, In my experience tend towards a particularly affectionate stance towards those they find in their social structure..." In real life I would get to "cat..." and someone would say "I've seen that musical, it was 1982 when my grandma died. Why did you never love me grandma! Oh god I'm so alone."
(Decently) effective puncuation can be just as, if not more, effective than body language. Frankly, I think most people aren't paying attention anyway because they are on or thinking about their phones.