It was like a Fight Club where we could project our primal selves, like a primal urge to just fight and shittalk and rage, and that probably sounds nasty to a domesticated modern, but it really was A Good Thing. It's really just good fun at the end of the day, but even further, it's almost therapeutic, whereas we all have to wear our masks throughout our day, but then we got to be the competitive, shittalking, carousing, brawling cavemen that live in all of us.
Fight Clubs are for practicing taking hits as much as dishing them out. You practice giving your utmost brutality, your meanest, your dirtiest, and you also practice taking others' nastiest, because the world can be mean and nasty, and playing at that is one way to explore just how nasty it can be. When we play-fight in peacetime, it hardens us, prepares us for wartime.
If you're only ever exposed to people at their best, how will you know how to deal with them at their worst?
It's unfortunate to see these Fight Clubs disappearing at an increasing rate, with the advent of so many safe spaces. We need the opposite of safe spaces.