"Zoe only has 1 damage spell"

Except that this really isnt true. Her Q may be MOST of her damage, because it has a low cooldown, high base damage and doesnt cost much mana, but her E has good damage on it as well, her W has magic damage when she uses it, and she gets a passive proc from every spell.

If Zoe buys a Lichbane, even her ult can deal good damage. Her E sleep proc deals double damage because the bonus portion deals true damage equal to what was dealt post-mitigation by the original spell that proc'd it.

I know that Zoe nerfs just went through and Riot is waiting to see how they do, but they expect that it should bring her in line, but IMO Zoe has too many one point wonders.

Her W gains damage on the active spell orbs when it is leveled, as well as movespeed and duration of movespeed upon activation. Why not increase how long Zoe can hold onto shards per skillpoint, or what types of actives minions can drop per level. So you dont get an exhaust/ignite/gunblade at level 3.

Her E gains slow %, damage and CDR on hit per level. Which is OK because the bonus damage on the sleep being proc'd is capped at what E's maximum damage is at that time. (There is literally nothing that tells you this in game, or the true damage portion, which is why her E proc seems to burst so hard, you have to look that up on a third party site.) Yet getting 1 point of E still lets the bubble sit on the ground for 4 seconds, still has sleep be 2 seconds long, still sends it 650 extra units though a wall. You could make it less of a one point wonder by making sleep duration scale 1/1.25/1.5/1.75/2 seconds, making sleep proc for 20/40/60/80/100% bonus damage, having the bubble last for 2/2.5/3/3.5/4 seconds. Literally not having such a loaded spell that it almost matches Jhin passive at level 2.

Forcing Zoe to take more of a risk with her ult by allowing displacements/grounding to halt her from porting back to her original spot when she ults. There is no risk with this spell at the moment, if someone understands how to use it.

All in all, still waiting to see how the Zoe nerfs in 7.24 impact her, but saying that she only has one damage spell is misleading. 3/4 of her spells have damage portions, her passive adds damage per spellcast (auto/spellweaving), and every spell but her ult is overloaded in terms of what it can bring, and what it brings with just one point placed in it.