Why?

so i see the same champs in every match. i see zed, graves, lux, ezreal, yasuo, udyr, shaco,, etc. in every game. i never see yorick, taric, varus, diana, lissandrakarthus, evelyn, urgot, twitch, kennen, sivir, sion, etc. also im getting tired of lux ulting me every 15 seconds, udyr never dying, and graves doing dmg more than baron. fix.