Her instant stun allows her to guarantee stopping you before you could ever hope to finish 1/4 of your auto animation, and she follows it up with an auto E away. God forbid you play a fucking bruiser like darius or garen with a relatively slow auto animation and you're just insta fucked for what feels like a bullshit reason.
Legit almost nothing you can do outside of her fucking up.
I also find it hilarious that a riven with DD rav conq can literally outheal and stay topped off against a 430 AD garen solo target spin. What a fucking joke, granted conq is the main issue there.