Cross-play is getting rather controversial in competitive game modes but it appears Microsoft and 343 Industries are leaning into it heavily, pushing for Halo Infinite esports with the feature on.
Console players are at a disadvantage when it comes to aiming capabilities since gamepads don't offer as much manoeuvrability and precision as mouse and keyboard which leads to game devs adding aim assistance in various versions to compensate. This compensation is often over the top and sometimes even on par with softer aimbots.
Such issues result in PC and console players often refusing to play PvP shooters with each other, one group can make quick and precise movements while the other can almost effortlessly make precision sustained fire that would normally take a lot of practice to master. To top it off, PC versions of each game is often infested with hackers as the platform is fertile ground for these bad actors.
Despite all that, it appears Microsoft and 343 Industries are going to power through the resistance and the blog post about the announcement doesn't really elaborate on how they will balance out the gamepad aim assist with the power of KB&M. The only thing they said is that everyone will be allowed to choose which input they want.
Anyway, the companies were pretty clear why they are doing this - they want Halo Infinite esports events to be bigger than any in history and tapping in both XSX and PC pools will allow them to do just that.