About this aim assist

@RockDokRockyah, the hud is so counter intuitive, and the crosshairs too, like you take the point from real life, bullet travels probably faster than the speed of sound, so you expect when someone is right dead center in your crosshair of a shotgun they should take at least some amount of damage,

but in bullet drop br game? all it takes is straife to a direction or a crough, and you get nothing

and that's *, you have to predict someone's movement from point blank range, less than 5 meters and you can still literally miss your shot if you don't predict the direction the enemy is going

@Eshshshssso the aim assist not only helps to aim at player but also to follow them around?

And what do you mean by slow servers or lag? I have ping around 40 so I don't understand how this can be lag

@damsonwhufndthisdude you really need to watch videos on aim assist in youtube :D
Aim assist pulls in/slows down crosshair when it is NEAR (~half hitbox size given what I see in the videos) the hitbox.
Thus when tracking or compensating it makes things much easier, it almost tells you when to stop correcting for enemy strafe, movement.
While on M&K same movement would usually just overshoot like you would be on ice without skates and then you start overcorrecting that and in the end have a typical video of a player shoot all around the model but not at it.

As for the servers - I don't know all the details but people here on forums say (can't find the post either now) that Respawn servers are just slow. Meaning that even when you have 40 ms ping you don't get (I assume) as accurate and as frequent info back from the server. That messes up predictions and creates cropping/teleporting on your end or bullets going through enemies because game on your PC predicted player movement incorrectly.
Read on how FPS games work and how client / server side prediction works, couldn't find an easy video on it.

Finally, regarding lag hacks - there have been and clearly still are software around that introduces lag making your game smooth but your model for others teleporting. Don't know how it works but I have seen it, I have tested it back in 2000s in Quake and it damn sure works yet you can't prove it (I guess) because you might as well just have a bad connection that's why only options here are allow players to use this hack and do nothing or analyze probably tons of information in the server-side to catch these players = usually not worth it for the developer company.