Tanks & Tanks w/ AOE CC
First off, there is a lot of safe damage out there.
But mainly the point I am trying to make is all tanks should not be treated the same. The reason why I like tanks is they have identities and a lot are very different from one another. That is why the much needed nerfs should be targeted and not universal.
The problem is the tanks that combo AOE CC and/or engages. Not only can Rakan get tanky and have a good shield but also knocks you up and has an escape. That theme is consistent with all OP tanks. If Zac's team has a lead or the other team can't match his team's engage he just keeps jumping, Q'ing and ulting. Cho is not only massive but if you come to fight him you will be knocked up and silenced, therefore greatly multiplying is 'in effect' tankiness. The more you can do the less tank you should get, similar to the safer you are the lower your damage ceiling should be. Good engages basically carry, should be far less free; especially when the other team doesn't have it.
Played as Tanks that don't need nerf:

Tanks that need nerf bc they can do more which makes them even more tanky making everything they do more effective:
