Why does my mother always favors my little brother?

[279]

my little brother is 18, he always turn off our wifi connection so that he can solo our internet connection and make it faster whenever he play dota or minescraft

he plays dota everyday for 8 hours straight and he is addicted to it...

I already told my mom about it but it seems that my mother is allowing my brother to be addicted in playing dota because she is not confronting him about it.

actually it won't bother me if my brother is not turning the wifi off and also allow us to use the internet but he is too greedy to do that.

he is cutting classes and skip studying because of it.
and my mother is letting him do what he wants.
he always been favored by my mother.
@brands I already told my mom about it but she seems to not care about what I feel and still denies the favoritism thingy although it's obvious that she favor my brother more than me.