I was a small child in junior high school (grades 7-9). I was bullied daily for those years. I was contemplating bringing my father's gun to school when I was in the 7th grade. Fortunately I didn't know anything about guns and couldn't even load it. I guess I got bullied so much because I was an easy target.
Every fight i got into in school my relationship with that person got much better not saying it was normal but violence did solve a lot of problems for me.
At that age kids don't have all the complex social skills of later life, especially male kids, fistfighting is (or was in our time) the main way of establishing hierarchy pre-puberty. It is also relatively safe as there is not enough mass and strength for serious damage at that age. After puberty success with girls starts being a big factor, and then other more indirect venues of social competitiveness. In our environment, fistfighting stopped at high school in better schools and after high school in bad (mostly trade) schools. It was mostly 1:1, rarely ganging up. But also a lot of bullying of the weakest. Girls were often assholes too, just more verbally and in other less physical ways. Kids don't have enough emotional regulation and IMHO male children should learn how to wrestle (as that is how most fights at that age go).