Why is Grevious wounds so much better and more accessible to ADC than APC/Tanks?
I'm not sure I'd call
much better and more accessible than
.
is a much better item than Mortal Reminder in terms of raw DPS and tank-busting capabilities. Armor penetrations also got nerffed pretty heavily this season, making Lord Dominik's and another armor pen item pretty much mandatory to just deal with tanky shinnanigans.
On the other side: morellonomicon offers GW for free and fits in a wide range of AP builds pretty easily. It offers a good mix of stats, and with GW: it can apply that in a massive area-effect on the back of abilities with 1500 range. Essentially, no risk, decent reward.
As for tanks:
will negate essentially all life-steal based sustain and then some against the user with how the return damage works.
Not the most elegant solution, but then again: the AD and AP choices aren't either.
Beyond that: most life-steal and spell-vamp-esque sustain is based directly off the damage dealt.
If a skill heals the user for 10% of the damage dealt and does 500 damage, it heals 50 HP.
If that skill is mitigated to 100 damage because of armor or magic resistance, it only restores 10 HP.
Why is Grevious wounds so much better and more accessible to ADC than APC/Tanks?
The capacity to counter sustain within HP, AD, and AP paths is pretty equal IMO.
Tanks don't really need GW to combat most forms of sustain, and everyone having limitations adds more strategic depth and intrigue to the game than just allowing everyone to homogenize into the same extremely generic position.