>All of this is beyond horrific.
Hot take: It's also totally unnecessary. The entire arms race is stupid.
Proper anti-cheat needs to be 0% invasive to be effective; server-side analysis plus client-side with no special privileges.
The problem is laziness, lack of creativity and greed. Most publishers want to push games out the door as fast as possible, so they treat anti-cheat as a low-budget afterthought. That usually means reaching for generic solutions that are relatively easy to implement because they try to be as turn-key as possible.
This reductionist "Oh no! We have to lock down their access to video output and raw input! Therefore, no VMs or Linux for anyone!" is idiotic. Especially when it flies in the face of Valve's prevailing trend towards Linux as a proper gaming platform.
There's so many local-only, privacy-preserving anti-cheat approaches that can be done with both software and dirt cheap hardware peripherals. Of course, if anyone ever figures that out, publishers will probably twist it towards invasive harvesting of data.
I'd love to be playing Marathon right now, but Bungie just wholesale doesn't support Linux nor VMs. Cool. That's $40 they won't get from me, multiply by about 5-10x for my friends. Add in the negative reviews that are preventing the game's Steam rating from reaching Overwhelmingly Positive and the damage to sales is significant.
I don't understand why do you think that having the option to have secure boot and a good, trustworthy sandbox for processes implies you cant run Linux on a VM or Linux beside Windows etc.
People always freak out when I mention secure boot, and the funniest response usually are the ones who threaten to abandon Windows for macOS (which has had secure boot for more than a decade by default)
I'm not super technically knowledgeable about secure boot, but as far as I understand, you need to have a kernel signed by a trusted CA, which sucks if you want to compile your own, but is a hurdle generally managed by your distro, if you're willing to use their kernel.
But if all else fails you can always disable secure boot.
Secure Boot cuts both ways. The techniques anti-cheat software are allowed to use on Windows machines aren't even remotely allowed on macOS machines.