I have noticed some things about champs that have been deemed "op"
Let's look at winrates. Before you start saying "win rate doesn't mean shit" you should realise that if a champion is losing more than winning, you have a HIGHER chance of winning if said champion is on the enemy team. Not to menton if something is "op" then they are winning games too easily, so yes wintate does matter.
46% win rate.... Sure he has a high skill cap but that is an atrocious win rate. If he was op then he would have at least 50%
49% win rate.... And fizz is one of the easiest champs to play... He should be pub stomping.
winrate hovering around mid forties. And before you say "zed is to hard for bronze skrubzz" you should realise he is not doing well in LCS either. The only lcs player I have seen have success on zed is bjergsen, and I don't think riot is nerfing zed just because bjergsen is a god.
The moral of this is winrate DOES matter and don't say x champ is op without any evidence.