Zyra is currently an extremely strong poke/control/burst/sustained damage mage who is squishy. Yes, she doesn't have a dash, no, that doesn't make her bad. Her E is so good at keeping people off her without even thinking about her R that she doesn't NEED mobility to function like a beast. She is currently one of the best forgotten champions in the game to the point where she's overpowered. I'm sorry, but Zyra destroys mid lane, bot lane, and even top lane if you're a decent Zyra player.
You're Diamond 5. You should know what's good and what isn't. Think about her strengths, her weaknesses, and how her kit synergies with her to make sure that all her weaknesses are covered. This girl can one-shot someone at level 6 if she's even slightly ahead, and is arguably one of the best zone/control mages out there, even though her damage feels like 24/7 burst.
Obviously, like every mage, she's countered by gap closers that she can't stop, but in that vein, she suffers the same thing that other no-mobility mages like, I don't know, just spit balling names here, VEIGAR face, and Veigar is currently seen as overpowered.
Zyras weaknesses are the same as Veigars weaknesses, and her strengths are as strong as his are.