It's a range thing. Imagine a cone coming out of your barrel. At close range, the cone is skinny. At long range, it is wide. This is the aim assist cone. Wider points give more aim assist than skinny points. At the wide points, those links show the degree of aim assist. And it is massive.

I understand how it works I just mean it's odd that when I shoot someone at range even with a max range 120 the cone always seems a lot smaller than people complain it is. I don't see the issue. If the range on 120s was nerfed there would be little point using them over 150s.