Can you elaborate how it is Lee Sin continues to avoid much needed nerfs for months now? The buffs you gave him for worlds (that were completely unneccessary in the first place) pushed him over the edge, and he has been overperforming since, being the best jungler for months now.
Lee Sin sits between 47-50% and ~50% presence in pro play. His play rate is high, but this isn't unusual for a champ that's as popular as he normally, especially not when he is also seeing pro play. Winrate wise, he climbs from weak to totally balanced over elo.
Therefore the only major reason to nerf him would be that we think the game is low on champ diversity since he's too fun - and we don't like punishing champs just because they are fun. You'll notice recently we have been trying to open up the jungle to lots of other popular champs instead (Darius, Garen, Morde, among others).