After all the input on here about Aim assist I went and tested it out. As a lifelong M&K player I felt like halo infinite felt fine on M&K. I plugged in my Xbox one controller and tested the Aim assist on training mode, spartan difficulty. Unlike other players I had no issues with the red rectangle, the aim assist worked the moment I used controller inputs. I noticed that hitting headshots with weapons like the BR, commando, sidekick pistol felt super consistent on the controller. The aim assist really did a spectacular job. When the spartan lvl bots straved a lot the aim assist felt quiet weak, then again it did the same on M&K.
I have no knowledge on the Aim assist in previous games, if the aim assist stays this way I will definetly prefer Controller over M&K as hitting perfect medals was just so much easier with weapons like the BR & Commando.