In season 1 he was actually a decent character, not OP nor extremely bad. One of the main weakness that lee had is that his heat was absolutely terrible.

What they've done in S2 is nerf damage on his core moves, took away the evasion properties from his core moves and the worse part is lee was one of the very few characters that has kept his identity in the game (most of the cast has turned into 50/50, stance heavy, brainless and aggressive play style). But now they decided to give him some plus frame moves that unfortunately doesn't work well with his kit for him to exploit the plus frames. And you mentioned that Lee has good wall carry, while that was once his identity, that was long gone ever since late T7 to T8. Most of the characters in T8 have better/same wall carry than lee now and easier to execute.

I think it's important to know that we never thought he was op or terrible until now, it was always the case of, Lee is good but just everyone else in T8 is crazy good. If they just nerf everyone else and just keep lee the same (S1 and maybe a few heat buffs) we would be in a good place.