They nerfed all HP on tank items not that long ago, and then nerfed the amount of HP cinderhulk gives. No big surprise there.
The theory was that tanks should have to build for specific sources of damage, so each item should only be really efficient against that type. So, Randuins for crit users, adaptive helm for magic dot etc. Problem is that often makes them so specific that you need an item per champion the enemy team just to tank them and not die, and that assumes they don't already have some inherent tank busting ability like % health damage or true damage.
You built Randuins against Yasuo? Well too bad because AP kaisa is out of control. You built MR? Well too bad Fio with her Black Cleaver is got a couple extra kills.
On top of that they keep encouraging tanks to build damage. How is a tank supposed to build damage and 3 or more tank items to handle all the different kinds of threats?
Also a lot of the Resolve tree except for Boneplating and Chrysalis are gated by slow build ups and timers. Everyone talks about how Resolve tree is so OP, but in reality almost all the defensive options are in one tree, so where else would you go?