How is riven balanced?

Can someone help me explain how riven is not op?? Yes, there are certain champion that wreck him but agaist most champion its impossible to lane against him or be even. He has a DASH that gives shield. He has a stun. He has a Q that lets him just over walls and knocks you. Early game its hard to even fight him after level 3 or even 2. because any good riven will time the spells so pretty much will do so much more damage. The only thing i see is that he does fall off late game. I just wish they would take something out of his kit. I just feel toxic when i see a riven im suppose to play against.