Riot has never fully done anything they promised, or said they would.
Remember when they said they were going to re balance assassins, so they had more counter play and were a bigger risk/reward? The ONLY assassin that truly got this was the remade Evelynn. You still got Zed, Akali, and other assassins that can burst you down in .02 seconds before you even have time to press Flash, and usually they still get the kill.
Zed has the most abusively safe assassin kit ever. He can farm safely even if he gets behind and still stay ahead, and he has insane mobility/utility built into his kit with his shadow and ability to get around any gank and get himself out free of harm, while still bursting you down in .02 seconds.
They re-worked some assassins like Leblanc, rengar, etc., but still didn't put a whole ton of "counter play" into their kit. Then fucked up sorry released the new Evelynn and only did what they promised with her, but made it so ridiculous she's useless playing against any team higher than Bronze by giving her a 9 year "I'm coming so run under your turret or next to your tank so I can't do shit" skill that tells the opponent she's near them and targetting them well before she can actually do anything, and all her other skills rely on, and is the only assassin who isn't an inssue ever, because to actually "assassinate" even a squishy she has to either be overly fed, or have her ult, which is on an insanely high CD.
WHen the frack has Riot ever done anything they said to the full degree? Hell even half way to what they said? Remember last time Assassins/Bruisers were broken? They said they wouldn't allow power spikes to happen again... lawls... ADC's out of control, runes out of control. Good job Riot. Tanks have been over buffed, or over nerfed since season 3, and they still can't get their idiotic balance team to figure out why.
Yet other moba's like Hots, Strife, etc. seem to do very well balancing out all their plethora's of champions..