First of all, Kalista does not belong there, she's a ranged coward who don't deserve to be with assassins. And for your question, this "issue" has been addressed every single fucking patch, and its always a straight nerf...Most Recent is Kat's rank one ult now has 90 sec CD I think. More painful nerfs are Talon's silence, Kass's silence, LB's silence, Yasuo's everything, Zed's everything, and all those Diana "balance changes". These champions are made so that late game, the ADC carry, like Kalista, don't get out of control with their mobility, sustain, and DPS. Of course, they also use their midgame damage and utility to build advantage for their teammates in the form of gank, with is very health teamplay. Later on, they can choose to join teamfights to take out high priority targets, or splitpush. They exist so that you don't just pick 5 ADC and right-click each other all day. And Riot hates these poor champions as well, almost all changes are not in their favor...shield on second tower, the remake of heal a while back, the dmg reduction buff on exhaust, more and more CC chains, and of course, fucking
, takes no skill to use but is like the most cost efficient item in game.
Personally, mobility and high damage is what I look for in every videogame I play. And especially the games on tablets and phones, if there's no character like that, I just go delete the game. Its what I kill and die for, and it's been nerfed to the ground SO MANY TIMES already. If a Zed manages to kill you late game with a combo, then you suck, you don't know that ONE SIMPLE ITEM can counter his ass, and you don't keep enough distance, and you don't know when to use that flash. And your team sucks too, for not offering any peel.