So you say assassin's get to much shit but say with Zed, you build Duskblade, Ghostblade, LDR, EoN and Sudden Impact, you bring a squshies BASE armor (without GA) to approximately (give or take per champion base stats) -12 which means you're doing more damage that what your ability states at level 18.
As with mages (without the ability to use sudden Impact) with Morello's, and Sorc shoes, and void staff, Zed's base MR goes down to only 2.
And mages with sudden Impact proc, well, guess what they're assassin's pretty much. Dropping MR to approx -8, I'm talking Diana, LB, Zoe (she's a burst mage who plays like an assassin), Akali, Ekko, Fizz, Kassadin, etc.
So yes, assassin's are BS. And the reason is bc of Sudden Impact. It needs to be like the old mastery and apply it to everyone who takes it. Not just certain champs who have specific abilities.
Not to mention their are items assassin's use to be tanky as well:
