I coached high school debate teams, neither that nor arguing shit over the internet are the real world because you aren't actually risking anything and they are, as we are exploring in this very post and thread, predictable.
When I played sports, we spent a fraction of our practices trying to mimic the real world scenario (scrimmaging). And even in a scrimmage, it's risk free, there are no stakes.
The lack of risk is exactly what makes it great practice.
Edit: I would go a step further and wager our brains aren't calibrated for arguing random other human beings in person we don't share assumptions, behaviors, and/or appearances with; I mean people have a hard enough time communicating with the people they've chosen to commit the rest of their life too, it's hard to conceive of being able to master a marriage without being in the marriage.