How is Riven balanced? (Genuine question)

http://imgur.com/lu6OeLg

#Greetings fellow humanoids!

Now before anyone gets fucking triggered and downvotes this post to smithereens just hear me out. This isn't a hate post against any Riven mains out there at all. I just need some tips and tricks about playing against Riven. Nothing else. You have your favourite champion, I have mine. You do you.

Anyway. I was just wondering. What exactly is it that balances Riven? Everytime I'm up against her it doesn't really feel like I can do anything to counter her. At all. She has so much mobility with her semi-low cooldown dashes, she has a fair amount of crowd control, she has really high scalings, she gains bonus attack damage for every spell cast and her dashes resets her auto attacks, she has a shield that actually scales with her AD (Offense = Defense?), she can make her basic attacks and dashes even longer whilst also gaining bonus attack damage and a ranged AOE execute.

And the worst part is. All of this is free. She doesn't need to use mana. She doesn't need to use energy. She doesn't need to build up fury like Renekton or Shyvana, oh no, she can do all of the above for absolute free.

So this is where my problem comes in. How do I counter this? My first thought was "Duh just build armor", but since literally every single Riven out there builds Black Cleaver and atleast one or two lethality items, if not even more, and her ult being a ranged AOE percentage maximum health execute, made armor seem like a dead stat.

Second thought was to kite. In theory, this seems like Riven's biggest counterplay. However, seeing as she has all of these dashes and probably build a Youmuu's and/ or a Mercurial Scimitar, I find it hard to actually kite her in practice.

Third thought was to engage her after she as used her abilities. This is more of an early game thing than a late game thing she's probably build 40% cdr at this point. However, her cooldowns aren't (in my opinion) that high early game at all and since she doesn't use any resource, I can't exhaust her of mana or energy.

So I'm pretty much at a loss here. I have no idea how to counter Riven. If any of you guys know how to, feel free to post it down below.