Comment by Retr0id
One way to do anti-cheat on linux without compromising the sanctity of your host kernel would be to run the game inside a hardware-protected VM.
Anti-cheat does not ordinarily like to run inside a VM, because then the hypervisor can do the cheating, invisibly to the kernel. However, technologies like AMD SEV can (in theory) protect the guest from the host, using memory encryption. (And potentially also protect from DMA-based cheats, too)
What you'd need is some way for the hardware to attest to the guest "yes, you really are running inside SEV".
Even with SEV, you need hardware passed through to the VM. That means either running two GPUs or hot-swapping the machine your GPU is connected to and hoping neither driver crashes and burns (which is what you can expect from any consumer GPU driver that tries to hotplug). The software will also break the moment someone finds yet another side channel attack to break memory encryption. Intel's attempts at secure hardware hypervisors failed so bad they took the hardware out of consumer chips.
In theory you could probably get it to work on some hardware given some boot configurations with some games, but what game developer is going to develop a bespoke Linux VM? And if not the game developer, what Linux developer is going to spend time developing a platform that caters to the wishes of closed-source, rootkit-driven anticheat developers?