[xboxnolifes]

> Online, it's often a show where you're playing to an audience

I think this is the most important part. It's not just online vs offline. Even how people converse in DMs differs from public postings (not as good as offline, but different than public online). Instead, many interactions are done with the intent to gather an audience that agrees with you, so you can beat down your opponent by what is essentially intimidation. Or at least make it fruitless for your opponent to even try to defend themselves.