What are you talking about?

1 - kernel anti-cheats ARE weaponized by hackers. This is not a matter of discussion unless you are into the AI generated HN news conspiracy.

2 - this linux feature should provide (if I recall properly) a very complex and flexible (not limited to "calls"), and performant, set of interactions between a set of anti-cheat processes and the set of game processes. All that as being non-root priviledge (I think you must be have the same effective user id). The actual and real parameter is the level of competence and creativity of the "anti-cheat" team which is a requirement of any "live-service games" with frequent updates.

3 - for FPS games where aiming skill is critical, anti-cheat are close to useless due to "external" AI based aim assist hardware.

1. They're not, not sure where you've seen that, not in western games at least.