I disagree on that, Riven has the same issue as Renekton when it comes to laning. They can both all-in you and cc you while they get their combo off then put enough distance between you and them before you have time to react.
Only difference is Renekton falls off. Riven stays relevant throughout the entire game. If you build damage on Renekton you blow up stupid fast. If you build tank your damage starts to become irrelevant.
If you build damage on Riven you're tanky as shit with a low cd AD scaling shield as well as a ton of cc and mobility. Not to mention having an AD steroid.
Riven's kit is insanely overloaded and she stays relevant throughout the entire game. All of her "counters" at least fall off and suffer from being kited/ignored mid-late game. While she just becomes even more retarded as the game goes on.
She's suppose to be a fighter yet she has:
2 Forms of AoE CC.
5 Forms of AoE damage.
5 Forms of mobility(Flash counted).
Why in the world does a fighter get so much shit.
Not to mention armor is pretty useless against her and only becomes more useless late game when armor pen becomes grossly overpowered.
If Riven is allowed to have such retarded mobility and cc along with damage then Garen/Olaf/Darius/Volibear and every other easily kited tank/fighter in the game should be able to.