Riot Games talk Vanguard anti-cheat for League of Legends and why it's a no for Linux
(www.gamingonlinux.com)
If running on an obscure platform avoids cheaters, that's still security by obscurity. I assume it's only a matter of time before the number of cheaters using that client grows to the point where they either have to invest in anti-cheat there, or cut support for the platform.
MacOS is not an open platform, so as long as apple support their efforts, they will be able to have kernel mode anti-cheat there when they want it.