First of all, what I mean by out tank is build tank states in attempt to beat her 1v1, aka what the tanks do. This doesn't work.
Out heal? To put it simple, she heals too much. She's not even made to be a "draintank" and does more drain tanking than Aatrox once mid game begins.
Actually I think Lee Sin just needs a small base MS nerf, 10 more seconds of cooldown added to his ult at all ranks, and then maybe reduce his lifesteal/spellvamp but that would depend of how hard the former are as nerfs. Why delete him? He's a fantastic idea of "the playmaker" style character that really makes people want to play the game. He's hard to play, but it feels very rewarding.
If I'm bias then prove it. Heck, you could also try to disprove my logic. Seriously, just try to. How do you counterbuild Fiora effectively? If you can't put up, then don't get up in the first place.