well for one you dont build hec right, for two hecs not really that good right now hes okay for solo que but he always will be unless changed since hes like eve where you get free kills on low idiots and just scale into them. Aka hard to do bad with. Vi is sort of okay because she doesnt require the most skill but still requires some (hence why my games look different than yours).
Most of the time the champion being "op" or not doesnt matter its just what it supplys to what elo. Playing in low elo super easy to gank with champions ,cc, and scaling champions work since players cant close out a game and cant deal with cc. Basically all you have to do is play super easy champions with those qualities and you will win more games than you will playing crap like yasuo.
Just a lil advice.