What, exactly, is zed's weakness?

It seems to me that Zed is horribly inbalanced in that he has no real weakness.

1-His shuriken harass has some of the longest range in the game (especially with clone, at which point he can hit from fog of war easily). 2-His clone swapping makes him incredibly hard to gank. 3-His ult makes him invincible during the 2-3 second animation 3-His burst at level 6 is ridiculous, even without any items.

If anything, you can argue he's limited by energy, but when it's nigh-impossible to capitalize on that due to him being either far away (because he can harass from so far) or you being dead, it doesn't seem like much of a weakness.

You could attack when he tries to cs, but then you run into the issue of eating a shuriken and being even anyway.

The standard play against him is to rush armor, while he builds damage - it seems wrong that laning against him practically mandates buying items to counter his damage, while he can just build damage - resulting in him being significantly deadlier mid-game.

Fizz can't escape forever because the mana cost is prohibitive, and he has no poke. Talon can't escape easily because he has to use his ultimate and it has no actual movement (just stealth, which can be countered), and has much much less range on his poke.

This is partly a rant, but it seems like Zed beats every other melee mid in every category.

It almost feels like Thresh - does everything well without significant drawbacks.