"So" that most bodybuilders and strongmen do it for the atavistic "big guy = strong fighter = alpha" image, whether they know it or not (what other possible reason would there be? Name me one that doesn't come down to that).
They do it because there is money and fame in it?
Fighting is never useless, unless you want to be at the mercy of others. All authority stems from violence. It also changes social dynamics a lot. Being the baddest motherfucker in the room means a lot in human interactions, we're still wired just like we were when we lived in small tribes.
Fighting is probably more useless than being able to lift heavy things and have an ''attractive'' physique in my life and as far as I can see for anyone in my surroundings. Very little authority stems from unarmed violence by the individual wielding the authority these days. Can't remember a social interaction in my life where the baddest motherfucker enjoyed advantages in human interactions or when I was at the mercy of others. Besides, isn't the baddest motherfucker hard to spot as muscles and size are not a proper indicator of fighting ability? Violent people get looked down upon here and fighting ability gets few people anywhere on the social economic ladder. Dunno what kind of barbaric hole of Finland you reside in, but in a modern society fighting is for retards.
The only situation I can imagine unarmed violence playing a role in my life is a bar fight, and they are extremely rare and very short in the places I go to. Though I won't argue that this guy is even close to the best fighter, his sheer reach and size does mean that in a bar fight the layman and a few leagues above the layman still should not fuck with him. This guy trains for explosive strength, lifting and pushing with his entire body. Boxing gloves and rules make him a slow turd, but without the gloves this guy can is hard to hurt and if he gets a proper hold of anyone half his weight, he can do whatever with them.