This is a completely different meaning from the stat he is talking about. The aim assist stat on planet db is how far of target you can be and still get a hit (for instance if i hit someone in the neck it might still give me a head shot bonus), where as the aim assist you are talking about is how your sights move in game between targets if they intersect. The easiest gun you can see the aim assist stat on is the vex, literally you can just spray this gun and over half of the rounds will be off target but they will still hit even though they shouldnt. The vex has %100 aim assist.

Yes sometimes when you're trying to aim at one thing at a distance and another runs by it is annoying but if you tried to play crucible without it you would realize it is actually important. It helps a lot hitting the moving jumping people while you're moving and jumping.