This is a pretty annoying problem for mouse and keyboard ones, because they aren’t even a rivals for controllers. This completely kills the Halo PC experience. Quite annoying that they playing too lazily and hit all their shots without even an effort, while the PC ones try hard without success, and there is not even a register of their shots (I speak mainly for Halo CE as well as the melee punch; which is a game that is pretty much forgotten by 343 Industries who do nothing about these issues).
Anyway, if 343 Industries really cares about the Halo PC experience, they should do something about it. Put aim assist on for PC, or remove aim assist for controllers, or separate the two platforms into different game rooms (PC vs. PC; Xbox vs. Xbox).