Lee Sin really shouldn't have the best disengage in the entire game while being so mobile.
It temporarily stuns you, deals a fuckton of damage, and knocks you and everyone else hit 1200 units away. That's longer than a Lux's Q. On top of this, the cooldown is very low, on a champion that often gets 30-40% CDR quite fast. Having the best disengage on a 36 second cooldown with some of the best mobility in the game is absolutely unnecessary. If you manage to catch him out, or flash/ghost/ult to get to him, he has 3 abilities to escape you, and with 40% CDR their cooldowns are 4, 8, and 36 seconds.
To me it just doesn't make sense how safe he is at all points of the game. Up until around level 11 he's pretty much the most dominant ganker and counterjungler in the game. He should be a champion that falls off like a rock, but instead he just transitions into a tank with disturbingly high utility. His mobility and burst is already as high as an assassins is, I just don't think he needs the amount of safety he has.
He's got a 35% playrate and a 51% winrate. Being one of the most mechanically difficult champions in the game, this means something is wrong. Either increase the cooldown of his W, his ultimate, increase his energy costs, or have his ultimate do less damage so it can't be used as both a disengage and a nuke that can do a ton of damage to the entire enemy team.
get to sit at 54% win rates because they're win rates aren't lowered as much by newbies/unskilled players playing him.