Anyone remotely familiar with operating system design can tell you that desktop and mobile operating systems have massive differences with respect to security. "macOS, Linux and Windows are not sufficiently "well-designed" OSes for this purpose" is exactly the case.
Ok, so what are the features missing from those OSes that iOS has that enable these anti-cheat capabilities and also that are also not dependent on Apple maintaining its strict control over what can and can't run on iOS?
A complete trusted boot chain, lack of third-party kernel modules, and remote attestation. Nothing runs in iOS kernel space without Apple saying so (which is NOT the case for desktop operating systems), which is a prerequisite for remote attestation (which iOS also supports).
None of these properties are compromised by allowing arbitrary user-space code, which is what is one of the parents thought would happen.
