This is because most anti cheats for windows are kernel level rootkits that have full access to your entire system, and gamers just trust that known to be ineffective, scammy and profiteering, anti cheat companies software companies would /never/ do anything nefarious.
How can you trust them?
You can't! Black boxed code, babyyyyyy.
Anyway yeah on linux systems basically the designs of all common anti cheat systems would be laughed at as hilariously insecure code that no sane person would allow on their computer because you would have to give it root level access.
This is basically insane as in the linux paradigm, root level access is reserved only for a bare minimum of system processes, whereas on Windows, well with the new Pluton tech in the latest lines of major CPUs, Windows has the ability to DRM literally anything you install on it and just get rid of your ability to run or install it, as they see fit, with a network enabled sub layer of the CPU that you as a user cannot override from within Windows.
The only hurdle for linux gaming is for more gamers and game developers to realize the truth of what I just said.
Its possible to do anti cheat in less invasive ways. But that requires more work from game development studios, and is costly.
Anyone else remember when servers had like actual human admins that would respond to player complaints, and would work on the backend of a server to come up with their own ways to detect cheating server side?