First of all, I never said I know zed better than you. I just said you havent played him in a while. Rank is irrelevant in this because anyone can look up anybody elses winrate for a champion. Playrate is what matters in this scenario, because if you are a main for a champion, your playrate for said champion will be significantly higher than any other champion.
Second of all, You can't say you main a champion you havent played in ages. That's like me saying I'm a Janna main, because I mastered her first, although the last time I played her was in ARAM. Although I did well, I dont play her enough to call her my main. If your "main" is weak, you still play them. You don't pick a main because they're strong do you? The reason a champion is weak is because the meta isn't for them. But the thing is, the meta doesn't have to be in favor of a champion to do well, especially if they're your main.
You can say you know zed all you want but knowledge goes away, as does skill when you don't do something often.
I played zed once by the way. I did terribly because I had never played him or against him at that point.