Just to be clear, the anti-cheat systems that support Linux run at the user level and don't require secure boot. Those kernel-level and secure boot restrictions only apply to a handful of games, and they all explicitly block Linux users anyway. For example, I've been playing Arc Raiders a lot recently in Linux, and the user-level EAC works just fine.
> ...Elden Ring uses EZ Anti-Cheat and it works on linux and that game is infested with PvP cheaters.
I would question how good Elden Ring's use of EAC actually is.
Given that -at launch-
* Players who were using a Japanese locale couldn't play the game unless they removed EAC
* Removing EAC substantially reduced the amount of incredibly noticeable hitching and stuttering
my hunch is that EAC was hastily slapped on very, very late in the process due to demands from some US-based PHB.
The user-level cheats are extremely bad. For example, Elden Ring uses EZ Anti-Cheat and it works on linux and that game is infested with PvP cheaters.