If Yorick got nerfed because he was too strong in low Elo, Riven should get nerfed because...
If Yorick got nerfed because he was too strong in low Elo, Riven should get nerfed because she is too strong in high elo!
Riven has a negative winrate in bronze silver gold and platinum, yet she still has an overall Winrate of 52%. This means she has an absurd winrate at high elo
Threat all classes the same!
Both require mechanics, but those mechanics are now "normal" to players nowadays, meaning it shouldn't be deciding how they are balanced % wise. You can kill a good Yas player, but its hell to kill a good Riven player.