I feel like the only reason Zz'rot is not used more is simply because it is still PERCEIVED as bad.

It's a strong item, the scaling on the minions being changed to %health was a really strong buff to it as well, as well as the range being increased.

Let's just break it down. For starters, let's just examine the STATS on it alone. 60 MR, 60 armor, and 150% health regen for 2750. Those are some VERY efficient and cheap stats. 120 in mixed resists for 2750? That's a god damn bargain, but what about the passive and active? 20% bonus movement speed near turrets, plus an active that scales massively with your maximum health and can push a lane quite far with absolutely no assistance.

So why is this item not used more? With so many new health stacking items around, you would think a super efficient mixed resists item would be very much appealing, but it's not. I feel like the reason it's not used is not because it's weak, but simply because it still has this stigma to it from when it legitimately was a lackluster item. But the %health scaling change really made it all that much better on anybody who builds heath.