@Kensukie Aimbot and aim assist are actually not the same thing.
Aimbot locks onto and keeps the player's cursor on the target, often times hitting the enemy player's head with near (or 100%) accuracy, while aim assist helps guide a player's cursor over to targets. However, it doesn't snap to the target, stay on the target, auto aim directly at the target, aim through walls, or aim for the player.
Recoil is also reduced for controller players as its slightly harder to control. Although a little bit of practice with aim assist turned off isn't a bad thing either.
I am a PC player who tried controller on PC, the aim assist was alright but it wasn't an advantage over a mouse and keyboard, (and often was my downfall), I've also played the game on friends Xboxes, the aim assist did indeed feel different, (60% vs PC's 40%), however it wasn't a game changer.
So yes, in short the problem is people using strike packs, xim, etc. which sadly it doesn't seem like there's a way to resolve that problem.