We are actually in a tank meta atm, just not the old tank meta

Why? Because with everyone playing AD champs who scale well with lethality instead of crit, and how they rush tanks are ridiculously strong atm. If you go tank top/jg/mid and build armor items ( , you survive FOREVER in a fight for the first 30-35 minutes of the game. Maybe even longer at lower elos where people might not pick up a LW item. Next patch, this is going to become even better with the changes to Black Cleaver and the nerfs to lethality.

The lethality users will try to ignore you and go for your backline, but even if they do succeed in killing them, they take forever to kill a tank. Even once they purchase a LW item, it still takes a while since they don't have the AS/Crit/Crit multipliers to deal the DPS to kill a tank.

TL:DR Tanks are incredibly strong right now, but only because people are building to kill squishies and ignore tanks. Its like playing rocks-paper-scissors where no one is playing paper atm. Therefore rock flourishes.