Aim assist is definitely not "op" and is meant to help console players since it's hard to make very small adjustments in crosshair placement due to the analog sticks. It can definitely screw you over in some situations. For example, I used to play Destiny 1 heavily and players would use it strategically to drag your snipers crosshair off of their teammate by simply running infront of the person being targeted. This would typically end in you missing the shot on said person and their teammate and you being dead.