Steam installs a system level background service to avoid UAC prompts. There was a privilege escalation vulnerability exploiting this service disclosed in 2019.

I did not say that kernel level anti cheats makes cheating impossible. The improvement in the experience is not nothing. You would not understand unless you played both for yourself.

https://www.faceit.com/en

Yep yep yep, the devs of the FPS game with endemic cheating so horrible the competitive scene had to introduce their own matchmaking system with kernel AC.