The iOS equivalent would be the app sandboxing mechanism, which very heavily restricts kernel access from most of Safari (most importantly the process that is J

The iOS equivalent would be the app sandboxing mechanism, which very heavily restricts kernel access from most of Safari (most importantly the process that is JITing javascript). It’s structured differently than SELinux and has some complications like entitlements that have led to vulnerabilities in the past, but it largely allows iOS to apply the same sort of app-level access control.