And even more than playrate, look at average games played. That tells you a lot. Sure, Jinx can have a 23% popularity, but her win rate doesn't take a huge hit since she also is #3 in terms of playerbase's average games played. So it's not like it's a bunch of people playing her for the first time.
When you want to look at something OP, look at Kog. He has the highest win rate, despite having literally the lowest average games played. So you'll look at it and say, "well he has a high win rate but is ranked 13/17 in terms of popularity, so it's probably only Kog mains playing him. that means only mains play him so his winrate is going to be higher." I'll look at him and say, "he has the highest win rate, yet people that play Kog are less experienced with him than people who play any other ADC. Meaning that the average person that plays Kog literally has no mastery of the champion." I mean, about 62% of people that play Kog have less than 15 games played with him. Jinx has about 23% of players with less than 15 games played. So her win rate should theoretically be higher.
Just something else to think about. But yes, I agree that Jinx needs nerfed.