Recent testing revealed that Arch Linux, Pop!_OS, and even Nobara Linux, which is maintained by a single developer, all outstripped Windows for the performance crown on Windows-native games. The testing was run at the high-end of quality settings, and Valve's Proton was used to run Windows games on Linux.
If you compromise your system with software that you don’t know and potentially can introduce a backdoor (even involuntary via bugs), you have a rootkit installed.
If you don’t trust it, don’t install it with admin privileges. Maybe don’t install it at all. Anticheat is a shady business. And mostly not owned by the company that produces the maybe trusted product to be protected.