Lee Sin was picked in every game of the worlds finals
and he won 3/5. You guys ready for next installment of the lovely jungle meta of Lee Sin only?
Honestly there's plenty that he has that doesn't need to be there. Ult has absolutely no business being so short a cooldown. The amount of time he has to decide whether or not to follow a Sonic Wave is more than gracious, and is disgusting for anyone opposing him to try and tank dragon or baron for an extra 6 seconds. Either make both parties unable to flash during his ult, or they both can, the wardhop->flash->kick is already a you-must-flash-to-escape-this for 75% of the roster, the extra handholding for Lee is not fair.
I find it hard to justify everything Lee has when the only argument is "he's hard to play well". Hate to break it to you but almost every champion who isn't currently broken is hard to play well, and in fact, Lee is easier to play because he's so damn forgiving "Oh you don't have 6 seconds+ of hard cc to catch me? Sucks to be you then.".