Gragas wasn't even that bad it was primarily only sejuani that was a real issue.
The whole reason i loved the Cinderhulk Meta was because most if not almost all champions (Poor Guy
doesn't fit anywhere) had a place and could be successfully utilized. Assassins had to actually pick their targets carefully and strike at the right time and pure tanks and bruisers had their distinct strengths and disadvantages while still being wholly different. Vayne was in her zone and fights lasted longer and could literally be swayed either way and the fight wasn't over until most of the enemy team was either dead or had retreated.
Then they had to bring about the awful assassin meta where Zed pretty much single handedly ruined the game for most people and he could kill tanks and bruisers like they were squishy adc's and he completely forced every other mid laner to rush Zhonya's regardless of who they were playing otherwise he would dominate.
Every meta we have had after the Cinderhulk Meta was just plain not fun and it took a long time for assassins to fully be toned down and put in a spot where they weren't completely dominant. During the Cinderhulk Meta they weren't a huge problem because if they went in at the wrong time on the wrong target they were dead and thats how it should be.