[rtkwe]

More likely is that some linux distro like SteamOS gets a large enough install base that it actually makes sense as a target and these big platforms make their anti-cheat work on at least that distro. As unfortunate as it is not having a very strong anti-cheat or a system like Valve's VAC ban to detect and lock cheaters out leads to really shitty online experiences in public lobbies for PVP games.

[Hikikomori]

Some anti cheat works with proton if the game dev allows it. But anti cheats are generally not effective on Linux because you can just load your cheat as a kernel driver.

[awakeasleep]

What kind of device & kernels driver attestation is possible in linux at the present time?

[Hikikomori]

Secure boot, signed drivers, attestation, is all possible. But you can just sign your own driver anyway so kinda useless.

Might be possible with a more secure mode that is booted into when you launch a game that only allow specific drivers and programs like the game and maybe discord.