Sit down and look at the patch notes for the past couple of months.
The exact same thing happens every other patch: a champion is very obviously over-buffed in one patch, then the next patch has something along the lines of 'oops, we totally overshot with the changes! ecks dee' and then the next patch follows up with 'haha, guess that little tap we gave them wasn't enough, here's another nerf!' and maybe, just maybe, they've been nerfed to a reasonable position.
This is happening with Shaco right now. He was very obviously buffed too much, and then after weeks of banning him, we finally get a nerf: box duration reduced to 40 seconds! Which is completely useless and has virtually no impact, because it doesn't do anything to address the main issue of how incredibly safe his assassinations are, with him only being visible for ~3 seconds at a time on top of having CC in the form of boxes and being able to juke burst with his ult.
Shaco is currently sitting at almost 55% win rate in Diamond+ (60% win rate in Master+), and Shaco mains are now pushing 63% win rate. This number is absolutely insane. I can't remember ever in the history of League seeing a champion with such a high win rate; the highest is normally around 60-61%.
This really needs to stop. I feel like someone isn't doing their job here.