Win Rate 45.5% in plat+ (pretty low right) 48.6% in Masters+ (Still kinda low)
Ban Rate 26.6% in plat+ Masters+ 40.4%
So while the champion might not be over performing. She is apparently so obnoxious to fight she is one of the most banned champions in the game.
Shes like 
but not dead.
And thats how you tell if a champion is toxic. Not great Win rate banned more then champions that are statistically better.
Honestly I think its more that her skill cap is insane and the folks who use her well demolish. Win rate being bad has a lot to do with low # of match players eating into her Metrics.
This is what happens when certainlyt gets to do whatever he likes. It's just his nature to make something with toxic design that causes frustration at an unbelievable level. Even if Akali is on your team she can be frustrating, not just if she's on your enemy team.
Like, look how overloaded she is (or was). Before the removal of her heal and true stealth and what not, she had like 8 mechanics total on Passive + Q. Not even Thresh has this amount on his entire kit (even though he's a support).
Akali's already a damn failure even from day 1. Hell, even if the entire design was on paper before getting worked is an obvious balance nightmare and how this even got the thumbs up as a good idea is beyond me. You can guess who's fault it is.
I remember this 1 match when i was trying to keep my eyes on Akali and she went so fast, my neck literally cracked because of how fast she went.
Moreso players dont understand how to play against her and assume shes good. Easier to ban than learn. Same with yas
