Well EAC for example is user space only because it has to be, which some games decide is not an acceptable level of security.

Those are generally not the same anticheats with the same levels of functionality. As an analogy it's like saying Excel supports iPad. Or a gaming example that used to be way more common: Tony Hawk Pro Skater 2 is supported on Game Boy Advance.

It's a game and it is Tony Hawk, but it's not really comparable as Tony Hawk on PS1.