User blog comment:C4bal/Corki in the Tank Meta. How to./@comment-24036535-20150614163022/@comment-4091261-20150619001040

On the contrary, the extra bit of tankiness and extra does save him. It's important to factor in that tanks, not an assassin, are mega-diving. While his allies may not be able to stop tanks form diving, they can stop the important damage dealers from reaching him--as they are honestly the only people his team should focus. If that is accomplished, tank damage output isn't as insane as carry or assassin damage. So, even a little tankiness is significant; as in terms of damage, tanks rely heavily on the base damage of their abilities.

If has 30% cdr, then he can easily get out of the clutches of tanks with a second, or even third  and then the enemies will either be too spread out or retreat eventually, which  can take advantage of since his team suddenly gains the upper hand.