Why should I pick Jhin

...over another ADC? As Jhin already has sometime sharing art in the game, some knockledge can be "done". I'm trying to main Jhin, but I don't see a reason to play him that makes him in a thing worth playing: mostly single target (or multi-target) can work (Vayne) but he attacks to slow, even with the 4th shot his damage is not as higher as someone who had a consistent amount of AS. And what makes him even more unworth, his that after all this lack of AoE OR DPS, he has no mobility at all. I don't see in what is him good at, cause I can't even 1v1 a Sivir at my level/items