The items are fine and if you want proof well if they were bad you would not build them but there are a lot of champions that build them.
Look at jg and support a lot of tanks are fine there but then you go to top and tanks are not good that shows the problem is the champions.
Look at the meta in top lane it is mostly sustain damage champions which already does well vs tanks.
So my way of making tanks come back is nerfing the meta top laners and buffing the tanks like mao,poppy,ornm,shen well any tank that's not mundo and cho.
But DON'T BUFF THERE ap or ad ratios no one wants that.
Maybe buff poppy's slow and the early game resistances on her w, lower maokai's mana cost. Things like that. While nerfing Irelia,aattox and darius.
Touching items and runes will do nothing unless you buff or nerf them to a stupid amount. Runes and items like conqueror and black cleaver are needed to stop tanks from being too good since it creates diversity.
Like what happens if you nerf black cleaver well you nerf champions are already not good like wukong and barely touch the meta tops since most of them don't build it, you nerf conqueror then we go back to tanks being too good and bruisers feeling bad.