The issue is doing the right calls more than proper champion pick. All sorts of bad calls. Including when to engage and not to engage.
If you are a really good support, you know what to pick, you are not gonna feed, you don't make bad calls, you ward properly, you sweep wards properly, you peel, heal or shield properly, but hey, that's not how you climb isn't it? You will eventually rotate to other position, want it or not.
I am assuming, that Kai is gonna also rotate roles, cause i highly doubt he will get support every single time. And that's also part of the deal, which favors him. If he really just wants to hardcore support only switching roles, he is on his own. May god have mercy on his solo q paths.