Already said it on the thread on !onehundredninetysix@lemmy.blahaj.zone: Unreal Tournament 2003 came with a bootable DVD that would boot into Linux and launch the game.

I Wonder if that could be a somewhat mutually acceptable anticheat solution. Launch any competitive game in a custom image that is locked down.

Back in the days of MS-DOS, there was something called "PC-Booters". They were created because of the fact that there was a lot of different operating systems that were actively used. So their solution was to just create a basic OS that contained the bare minimum required to run the game.

Systemd-boot detected