Tank meta exists specifically because of CC.
We are right in the middle of the tank meta, but that isn't because of a lack of damage -- because of the power creep, more champs deal devastating amounts of damage right now than ever. The reason we're in the middle of the tank meta is because the vast majority of all tanks have multiple forms of cc.
Honestly, it's ridiculous how much CC is in this game that tenacity doesn't even affect. You actually have a ton of champs coming out now that have high mobility, damage, and forms of CC as well. Back before CC was even OP, they had champs like Olaf and Irelia who were made to keep the power of CC in check, but for some reason, they decided that CC should be the primary mechanic in this game, and that characters like Olaf and Irelia should be nerfed multiple times (in spite of bad win rates), in order to enable that CC.
Nerf CC = nerf tanks.