Magic pen runes and Armor Pen runes
I like how people complain about Leblanc Damage, but never actually checked her runes. Leblanc runs a 9 AP , 16 Magic Pen, Hp Per level runes. Back in my days she used to Run Flat AP Quint 15, Mark Pen, Mana regen Seal and AbilityPower per level. Right now Magic resist is abundant, That is why Most Leblanc will run alot of Magic Pen to do consistant Damage.
Here is the AP Meta Pen for assassin AP.
Now Lets take Zed for exemple.
They nerfed Armor Runes from 13 to 9.
Armor pen runes are 13.
9-13= 4 less armor to mages.
A Heimerdinger base armor is 19.
19-4= 15 Armor.
Don't forget the Masteries Armor pen per level. 5.4 at lv 18
Here is the Ad Meta for any Ad champion:
A Heimerdinger at lv 18 has 70 base armor: 70-5.4-13=51.6
Now I'll let you guys think about it.
It is possible for AD champion to do True damage on a squishy. Increase Attack Damage on Item, Ad ratio is a bad way to increase overall damage against tanks.
The problem with Tanks right now like Volibear, Maokai, is that Grievous wounds doesn't impact their healing capabilities.
Sustain For Ad champion and Tanks are over the chart.
And Champion like
runs rampant on the rift.
with masteries offered 55%+30 armor penetration, and 50%+50 is needed to deal double damage (assuming 100 armor).
gets to 75 armor from bases, and with runes and masteries it wasn't uncommon for squishies to get to 100: which allows armor penetration to be a fatnastic secondary damage multiplier for AD Burst that was on-par with IE Crits for marksman.
The problem with Maokai is more that Maokai does everything a tank needs to do, which is why he's frequently surfaced at the top of the competative scene every year.
Volibear is more a result of fighter itemization being added this season that's really solid, Volibear largely being the average tanky DPS champion, and fighter itemization resonating more with him than anyone else due to it offering exactly what the average fighter needs.
Grievous wounds was awful in seasons 3~5 in regards to countering Voli and Maokai, what with Ex Calling and Ignite being the only 2 tools there, and Ex Calling being arguably the worst item in the game for that time span. Considering Ex Calling is actually worth purchasing this season, applies the debuff for twice as long, is less than half the price, and has a solid upgrade:
I wouldn't blame GW being 20% weaker as the reason either of those champions are doing well.
Major issue with GW is also that it's rarely useful on more than 1 champion on an opponent's team rather than it not being useful vs. that champion as well.