According to Champion.GG 4/5 of the top Ban Rate spots are taken by Yasuo and Irelia
Despite this, neither champion has an absurd winrate. Irelia sits at 50% wr and Yasuo has a 47% winrate. They both, however, have something major in common that is likely the cause of their extremely high ban-rate; They're EXTREMELY good at countering ranged champions, and probably exist as the undisputed best when it comes to Melee Vs Ranged interactions. Yasuo can (when in a decent spot), do well against ranged champions from level 1, and Irelia is reliably effective at taking out ranged targets in teamfights. (She's always been good at it, but now she's super good at it and in turn, has sacrificed some of the skirmisher bruiser vs bruiser power that her previous iteration had)
My theory; The hate that Yasuo gets, dare I say it, is actually quite unwarranted. The reason people hate Yasuo with such vitriol is because he disturbs an imbalance that has existed for years in League of Legends: Ranged Champions hold an inherent and arguably unfair advantage over melee. Yasuo and Irelia however deny this, as their hyper-mobile kits allow them to stick to a ranged champion like glue when certain conditions are met. This requires the ranged champion to adopt an atypical playstyle to deal with them; At lower levels, players might struggle with the mechanics or mindset necessary to play against these champs - leading them to cry Broken, Brainless or OPed. At higher levels, while players can quite easily shift in playstyles, they might still resent the fact that they have been required to do so in the first place.
Meanwhile Melees have been forced to deal with aids like Vayne top since time immemorial. /post