Well there is a purpose - it’s to see which thug can give a stranger a skull fracture. Extra points if the victim dies. What part of “game” don’t people understand???? /sarc
No sarcasm tag required. Many murder cases that are solved came to be solved because the perps knew the victim in some capacity, and the chain of friends, acquaintances and neighbors questioned eventually came round to them. Smacking a random stranger on the head is a way of murdering with impunity because of the difficulty of linking perp and victim. These are serial killers who aren't even being stealthy about it.