I'm certain most users don't know what they're agreeing to. It's sort of the same argument people make about Meta et. all spying on people. Well, it's not spying, because you agreed to the EULA.
Who reads the EULA? Nobody knows what they're agreeing to, ever. Even for computer-savvy individuals, do they know all of what the kernel-level anti-cheat does? Of course not. Even their consent isn't informed. For normal users, they don't know anything about anything.
If a user agrees to a kernel level anti-cheat, it's not a rootkit.