The endless cycle of horrifying metas is becoming stronger

Remember that moment where the meta was awful in season 5? When it was awful all through season 6? When it is awful right now? Didn't you wish you could get onto the next one so that you'd be as far away from the current one as possible? Well turns out it cannot be stopped and is getting more horrifying every time. You find one champion a total nightmare, and the next day it's two that are even worse.

Moments of clarity come once every 6 cancer metas, and I'm afraid we didn't appreciate them when they were still here. What moment in recent times has been the most balanced, and has been the best for champion diversity (something that Riot doesn't want to address)?